Lapping scope rings

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • Definition of lapping?
  • Scope ring alignment
  • Potential misalignment problems
  • The holes in the scope rings don’t line up
  • The inside of the scope rings are out of round or not finished smooth
  • Lapping scope rings
  • Check scope ring alignment
  • How are scope rings lapped?
  • Finish the job
  • Want to do it?
  • The big deal
  • Summary

This report comes by request of Pyramyd Air. It’s a subject that is not that familiar to airgunners for reasons I will explain at the end.

Definition of lapping?

Lapping is the polishing of surfaces to knock down the high spots and even-out the surface. I have addressed lapping the inner surface of a rifled barrel in the past, though I haven’t gone into it in depth. Today will be the first time I have addressed lapping scope rings.

Scope ring alignment

Scope rings are supposed to align with each other so the thin scope tube is held tight by the rings without any undue pressure resulting from misalignment. If the scope tube is perfectly round and also perfectly true (in a straight line along its entire outer surface), the holes in the scope rings need to be the same. If they are not true and also in alignment with each other, they will put uneven pressure on the scope tube when the rings are tightened.

Potential misalignment problems

There is a long list of potential scope ring misalignment issues. I will address a couple of the biggest ones.

The holes in the scope rings don’t line up

This happens more with 2-piece scope rings because their positioning on the gun is independent of each other. We presume the makers of one-piece rings take care to align them during manufacture. But two-piece rings can be out of alignment because of the scope bases they are mounted on. They can be off side to side and even up and down. It only takes a small alignment offset to create a problem.

The inside of the scope rings are out of round or not finished smooth

Cheap scope rings can have burrs and rough edges inside them that causes the scope to not fit the ring tightly. On really cheap rings it is even possible for the hole in the ring to not be round. Some are so bad they are not worth trying to fix.

Lapping scope rings

For these reasons and more many shooters have lapped the inside of their scope rings. Lapping corrects most of these problem, though if the base the rings are mounted on is the problem, lapping may not be enough. Some gunsmiths fail to take the care required to attach the scope bases to the rifle and create a problem that costs a lot more money and effort to be expended. This is far more common with firearms than airguns these days because most air rifles come with scope bases already machined into their receivers or scope tubes. 

Check scope ring alignment

To lap a set of scope rings you first mount the rings to the rifle. Then use a special pair of alignment tools that are the same diameter as the rings and taper to a point. When they are mounted in each ring with their points together, they either prove the scope ring holes are aligned or they show the misalignment.

scope ring align
Scope ring alignment tools.

ring misaligned
This is what a misaligned set of rings looks like when the tools are mounted.

If you don’t have these alignment tools you can use the lapping bar, though it will not tell you as much. A lapping bar of the same inner diameter as the rings is set in the lower ring halves. The bar looks like a scope tube. If this bar just drops into the lower rings you can proceed, but if the bar will not drop into the lower halves of the rings you must investigate why. This is where the alignment tools really pay off. 

You may discover that there is a fundamental problem that prevents proceeding. Or you could just stick the scope in the rings and try to mash it down into place by tightening the top ring caps. I have seen that done and it usually results in a dented scope tube, if not a broken scope.

How are scope rings lapped?

Scope ring lapping is grinding the inside of the scope rings to fit the outside of the scope tube. Let’s assume the lapping bar did fit down in the rings as it’s supposed to. Step one is to remove any material from inside the ring so the lapping bar can contact the ring directly. Some rings have non-slip pads inside and they must be removed.

The lapping bar is then coated with lapping compound, which is a fine grinding paste. Put the ring caps on over the lapping bar and snug them down, but not so tight that the bar can’t be moved. Now the lapping bar is both rotated and worked back and forth just a little to remove the high places on the inside of the rings. As you rotate and work the bar around, tighten the cap screws every so often, so you get an even lap. Lapping should go very quickly, but that does depend on the material from which the rings are made. Aluminum will lap much faster than steel. As you lap if you remove the bar and clean the rings you’ll see the high places that are being worn away.

Finish the job

Remove the lapping rod and clean off all the compound from the rings. Clean the lapping bar too. Then replace any material you may have removed from the rings before lapping if you really want to. A lapped set of rings will grip a scope much better, so the material may not even be necessary

Want to do it?

Lapping compound is sold in many places and is easy to find. Make sure it’s for the material your rings are made from.

A complete lapping kit can be purchased at several places online. One for both one-inch rings and 30mm rings will run about $75 and up. It includes both the alignment tools and the lapping bars in both ring sizes.

The big deal

Okay — if the rifle is an airgun and IF you buy quality rings, they probably don’t need to be lapped. Today’s scope bases and scope rings on and for airguns are very high quality. Lapping is more for the firearm user who uses two-piece rings and had to have two scope bases installed on his rifle by a gunsmith. There are so many variables there that lapping is still a viable option. But with a good set of airgun rings on a modern air rifle, lapping should be a thing of the past.


Scope lapping will never go away as long as gunsmiths attach ring bases after the gun is made. This happens a lot with older military arms. Modern firearm should come with bases that are in alignment, and the use of the Mil Std. 1913 Picatinney rail system has all but eliminated scope base issues. Combine that with a set of quality rings and the need to lap all but disappears.

Let’s make lemonade

by Tom Gaylord
Writing as B.B. Pelletier

History of airguns

This report covers:

  • Lemons
  • The bigger picture
  • Whodunit?
  • So what?
  • They got better
  • The point?
  • Summary

I was all set to begin telling you about my Beeman 400/Diana 75 today. Yes — my rifle is a Beeman 400. I’ve had people tell me Beeman didn’t sell a 400, but I’ve got one to show you. However — not today.

There is one part of the Diana 75 sidelever recoilless air rifle that I had to discuss with you first and, as I thought about it, this one component is more important than the entire target rifle. So today I tell all of you how to make lemonade. Some of you will make it, some will even set up lemonade stands while others will continue to curse the darkness.


The world of airguns is replete with lemons. In 2018 I told you the story of a Benjamin 700 that was practically forced upon me at the 2018 Texas Airgun Show by one of our regular readers — I forget who. The price of $95 was certainly good. But then I had to get it fixed and, by the time that was over, I had three times the money invested in the airgun. By the way, that BB repeater now holds air indefinitely and is looking for a new home.

The Schimel was a new CO2 pistol in 1950. It was unique, in that it was a CO2-powered .22 pistol that shot pellets at 550 f.p.s.! However, unlike Crosman who had been building CO2 guns for decades by 1950, the Schimel was made with high-tech all-new materials. Unfortunately many of them did not withstand the test of time. The metal parts welded to one another through electrolysis, the o-ring seals absorbed gas and locked the gun up tight for hours after the cartridge was empty, the paint flaked off all over the gun and the plastic grip scales shrunk and warped over time.

The Schimel looks like a P08 German Luger and my wife, Edith, who saw the air pistol first, always called my 9mm 1914 Erfurt Luger a Schimel. 

The bigger picture

Those guns and others like them were unsatisfactory, but they were nothing compared to the tens of thousands of failures that were foisted upon the airgunning public in the 1960s and ’70s. Companies with solid reputations that we still trust today sold tens (hundreds?) of thousands of premium airguns to unsuspecting customers who only found their Achilles heel a decade later. Their piston seals were made of the wrong synthetic material! That material worked well when it was new and fresh but it hardened in the air and slowly turned into a dark yellowish waxy substance that fell apart in small chunks. I have found bits of brownish-yellow wax in the barrels of dozens of these airguns. Not one of them escaped this fate and in 2021 there isn’t one of them that still has its original seals.

124 perished seals
This FWB 124 pistol seal was white-ish when new. This brand new seal has never been in an airgun. Years of exposure to the atmosphere have turned it brown and dried it out. It does the same thing inside an air rifle.

I wrote about one of these airguns in the 15-part series, A shrine built for a Feinwerkbau 124, back in 2010 and 2011. Yes, the legendary Feinwerkbau put the new bound-to-fail synthetic seals on their iconic 124 (and 121, 125 and 127). That’s tens of thousands of airguns, right there! And yes, I did write a 15-part report about the 124. I also wrote a great many more reports about that model over the years. Many of them have been about replacing the original seals with ones made from modern materials. I have probably resealed 12 to 15 model 124s in my time.

Okay, get angry! Why would such a prestigious airgun manufacturer put something that was bound to fail in their finest products. Let’s see. Perhaps they didn’t know?

Why would Coca-Cola change the formula that made them the world’s leading soft drink producer? Why would NASA skip some of the testing for the Hubble Space Telescope before launching it into orbit? I could go on but the answer is always the same — they didn’t know.


Now we come to the part of today’s report that explains why I didn’t start presenting the Beeman 400/Diana 75 today. You see — Diana also used this new synthetic material in their piston seals. That makes the following models subject to early failure.

Diana 5 pistol
Diana 6 target pistol
Diana 10 target pistol
Diana 60 target rifle
Diana 65 target rifle
Diana 66 target rifle
Diana model 70 rifle
Diana model 72 target rifle
Diana model 75 target rifle

And the companies that sold these airguns under other names, like Beeman, sold them under different model numbers, as well. But wait — there’s more!

Walther also used this synthetic material in their airguns made during this same timeframe. That made the following models that are prone to early failure.

Walther model 55 target rifle
Walther LGV target rifle
Walther LGR target rifle

I have resealed two LGVs for this problem, and I paid someone else to reseal one because he wouldn’t sell me the parts. I have an LGR that was also resealed.

So what?

BB, you’re painting a dismal picture here! This is why I won’t buy a used airgun.

Well, you do what you think is best, but I am telling you that this has opened up a grand world of opportunity to those who can work with it. You can either complain that the lower 40 acres on your Titusville, Pennsylvania, farm is all full of black sticky muck that clogs your plow or you can arrange to sink an oil well and become a millionaire!

Guys, what BB is telling you is there is a huge stock of wonderful airguns rotting away in closets because they suddenly stopped shooting when the barrel filled up with the brown waxy stuff. They would have been thrown away years ago but the supply of round tuits was temporarily exhausted. It’s hard to hold an FWB 124 or a Diana 72 in your hands and not realize what a diamond it is!

They got better

All those prestigious companies who were bamboozled by the early synthetics (remember, Benjamin Braddock — plastic is the future! {from The Graduate}) learned their lesson and made their seals out of new material that lasts virtually forever. They each went a different way but all of them figured it out, just like General Motors figured out that timing belt gears should not be made out of Nylon!

While “they” were figuring it out, the aftermarket guys also got with the program and better synthetic piston seals began showing up worldwide. So today a 124 that’s no longer being used is a loving puppy that needs to be adopted. I once bought one for $35 — from an airgun dealer! I bought a nice one for $200 a few years back — from a gun dealer who took it on a trade in for a “real” gun. That one I still have.

I even bought a 124 complete action in a deluxe stock at a gun show for $50 a few years ago. But I sold that one to another airgunner who said he had a barrel.

The point?

If you haven’t gotten it by now, bless your heart! What I’m saying is that there are thousands of worthy airguns laying around that are simply in need of a new piston seal. These aren’t cheapies, either. These are good airguns. Just look at the list up above again. But their owners don’t appreciate them anymore.

I bet if there was a pristine 1957 Chevy Bel Air parked out in the street and the For Sale sign said its original 283 original engine was’t running, people would find a way to do something about it! BB Pelletier just told you that there are thousands of them and you just have to look for them.

Look in odd places. Don’t look in the car trader magazines for ’57 Chevys. Everybody looks there. Look behind the body shops and repair shops around town. That’s where the mechanic parked them, waiting for the owner to pay his bill. And he never came back. Sure there is no title, but we are talking about airguns — not cars! Don’t need no title for an FWB 124 or an RWS 75.

Read the ‘spensive Gun Broker ads that say “I don’t know how well this RWS Diana 75 rifle works because I don’t have any pellets to shoot in it.” Sure — we all believe that. So you contact that guy and tell him that a piston seal replacement for a Diana 75 will cost you at least $350 — $250 for the work and parts and $100 for shipping both ways. Tell him you’ll give him $250 for his $575 air rifle, plus $50 to ship it and then, if it does have the bad piston seal problem, you do have to pay the rest to get it fixed. And you come out about even. But if it doesn’t… oh, happy day!

Or, you can fix it yourself. Or, you will luck out and discover that it works fine. Or, the seller will discover that he actually does have some .177 pellets and the gun does, in fact, work. Then you ask him what pellets he has and what velocity the rifle shoots them at and he tells you that he doesn’t have a chronograph. And on and on…


Now I’ve told you all that is behind the piston seals of a Beeman 400/Diana 75. That means that on Monday you can light just one little candle and stop cursing the darkness.

A little about o-rings

by Tom Gaylord
Writing as B.B. Pelletier

An assortment of o-rings.

This report covers:

  • History
  • Flexibility is key
  • O-ring failure
  • O-rings as a face seal
  • O-ring-assortments
  • Hardness
  • Some o-ring facts
  • The seats or channels they sit in help o-rings work!
  • O-rings used other ways
  • Summary

An o-ring is a donut-shaped elastomer (pliable) seal that performs sealing functions for hydraulics and gasses. Airguns use o-rings a lot, and for different purposes. They help us enjoy our hobby with a minimum of fuss. But what do we know about them?


The first patent for an o-ring was by the Swedish inventor, J.O. Lundberg. It was granted in 1896. Not much is known about him, but Danish machinist, Neils Christensen who came to the U.S. in 1891, patented the o-ring in this country in 1937. No doubt his work originated from his development of a superior air brake that Westinghouse, a leader in air brake technology since George Westinghouse invented the first fail-safe railroad air brake in 1869, gained control of. In World War II the U.S. government declared the o-ring a critical mechanical seal technology and gave it to numerous manufacturers, paying Christensen a stipend of $75,000 for his rights. Long after the war was over and he had passed away his family received another $100,000

Flexibility is key

For an o-ring to work it usually needs to be flexible. One of the most noteworthy failures of an o-ring that was not flexible was the space shuttle Challenger disaster in January, 1986. Caltech physicist and Nobel laureate, Richard Feynman demonstrated that the cold experienced during launch as the rocket rose had hardened the large o-ring that sealed the right solid rocket booster to the point that it crumbled in failure. Let’s see why flexibility is so important.

An o-ring sealed two adjoining parts (top and bottom)

o-ring under pressure
When under pressure (gas is coming from the left in this drawing), the o-ring deforms and presses against the tiny opening at the upper right, sealing it tight.

In both drawings I have made the clearances between the parts larger than it should be, to make it easier to see.

O-ring failure

O-rings don’t just fail in aerospace applications. We have seen them fail from rigidity in airguns, too. Read the report titled Crosman Mark I and II reseal to learn a lot more about them. In those two reports we saw how a hardened o-ring crumbles when it’s removed, and how a fresh one reseals the airgun instantly.

Another way an o-ring can fail is if it extrudes (gets squeezed through) the opening it is trying to seal. That happens when the ring material is too soft for the application or the tolerances between parts are too great or the o-ring channel is cut improperly.

O-rings as a face seal

We also see o-rings used as face seals in some airguns. One common use is as the breech seal of a breakbarrel airgun. I have shown you this many times as I rebuilt Diana air rifles over the years. The most recent was the Diana 27S, whose breech seal had hardened from the passage of time. When I replaced it with a fresh o-ring the rifle gained some velocity, though not the 300+ f.p.s. I initially thought.

Diana 27S breech seal
Diana breech seal.

Not all breakbarrel breech seals are o-rings, even though they may look like they are. Weihrauch has used specially designed breech seals that appear to be o-rings when they are installed, but when you examine one outside the airgun you see a big difference.

Weihrauch breech seals
Weihrauch breech seals look like o-rings when they are in the gun, but they are not.


Beware, because here comes The Great Enabler! Several months ago I realized I was buying o-rings one at a time for projects as I needed them. That’s not the wisest thing for a dedicated airgunner to do. So I went online and searched for assortments of o-rings. I found many and it came down to two things — what did I need and how much did I want to spend? For me this is a business expense, so yes it comes out of my pocket — sort of. But when I buy something like this I get to spend it before Uncle Sam can.

When you need an o-ring they are specified by their internal diameter (ID) and the diameter of the ring material. The outside diameter (OD) of the o-ring is just given for informational purposes, because when you think about it, the ID and ring material size determine the OD automatically.

I bought an SAE assortment and a metric assortment, but because they are pliable , they will interchange if they are close. If you want to get really picky, o-rings come in aerospace standard 568 (AS568) and ISO 3601 sizes. They also come in a wide variety of materials with Buna (Nitrile), Neoprene, Urethane, Viton, Teflon (PTFE) and Silicone being some of the most common. Airgunners tend to use Buna, Teflon and Urethane. Buna is more pliable and Urethane is more resistant to tearing and abrasion.


A lot of people use the term durometer when referring to o-rings without understanding it. A durometer is a test instrument that measures a nonmetallic material’s resistance to puncture and abrasion. The Shore scale is used. When we talk about o-rings I see the term 90 durometer tossed around a lot. A 90-durometer rating only has real meaning when matched to the Shore hardness scale to which it applies. On the Shore 00 scale a 90 rating is medium hard, while on the Shore D scale a 90 rating is extra hard — almost as hard as it gets! Your car’s tires are a zero to 10 on the Shore D scale and a 90 on the Shore 00 scale.

Some o-ring facts

1. To perform correctly, a hard o-ring needs tighter tolerances than a softer o-ring.
2. An o-ring usually needs lubrication to do its job – but not always.
3. When an o-ring seals something, it only needs to be finger-tight.
4. An o-ring can look fine yet hide a tear or a puncture that will leak under pressure.
5. An o-ring can look ratty yet still seal perfectly.
6. The durometer rating of an o-ring can change over time, as it hardens.

The seats or channels they sit in help o-rings work!

If the seats are too wide or too deep, the o-ring will not seal the joint as intended. Also, the shape of the o-ring seat or channel is somewhat important. While there is a lot of room for slop with an o-ring (that is one of their endearing qualities), you can’t get away with murder. A perfectly square channel with no radius in the corners may present sharp edges to the o-ring under pressure. It can cut the o-ring, causing it to fail quickly!

O-rings used other ways

Besides seals we find other uses for o-rings in airguns. Sometimes they are used to hold things together — sort of like precision rubber bands. I find that a lot in silencers. And a number of rotary magazines use o-rings to hold the pellets inside in place. I’m sure they are used in other ways, as well. We owe a lot to the common o-ring


There is a lot more to know than what I have presented today. These have just been some of the basics about o-rings. We deal with them so much I thought it would be nice if we knew a few things about them.

Crosman Mark I and II reseal: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Crosmnan Mark schematic

Today’s report is another guest blog from reader Ian McKee who writes as 45 Bravo. He’s going to finish the report on resealing the Crosman Marks I and II CO2 pistols.

If you’d like to write a guest post for this blog, please email me.

History of airguns

Part 1 — resealing the end cap

Over to you, Ian.

Crosman Mark I and II reseal

Ian McKee 
Writing as 45 Bravo

This report covers:

  • Disassembly
  • Bolt removal
  • Hammer spring
  • Remove trigger guard
  • Remove the valve
  • Prep and assembly
  • The 4 o-rings in the pistol
  • Piercing cap o-rings
  • Assemble the pistol in the reverse order
  • Test the function

So, your Crosman MK1 is still leaking, even after you replaced the seal in the piercing cap as we covered in an earlier blog. 

There are only 4 o-rings in this pistol, only 3 have constant gas pressure on them when the gun is charged, and 2 of those are in or on the piercing cap assembly, and those we already covered. 

If you have an interior leak, 99.9% of the time, it is going to be the nylon seal inside the valve stem assembly. I will show that at the end of the disassembly.

Replacement valve stem assemblies are available online from several sellers. Some are made from Delrin, with a steel valve stem inserted. Others are made from brass and steel, with the Delrin or nylon valve seat like the factory ones were made.

Some sellers sell refurbished original valve assemblies and require you to send in your old valve stem assembly as a core exchange, so they can rebuild and resell it; others make an entirely new assembly and sell you that. 

If you have the skills and tools, you could remove the old stem assembly, remove the damaged nylon seal, and make and press in a new one. There are videos on youtube that does show that process. Unfortunately, there are a lot of steps just to change out the valve stem assembly, which has a nylon seal inside that is literally the heart of the gun. 

This reseal is going to be a little different, as I will include the Crosman part numbers as shown on the exploded parts view. That will help you keep track of the little bits and bobs.

An owners manual and parts view are available as A FREE DOWNLOAD FROM CROSMAN.


Make sure the gun is unloaded, and degassed.

Take the grips off, put them and the screws in a safe place. Also remove the piercing cap.

Loosen one of the small rear sight windage adjustment screws (140-009).

While holding the pistol upright, carefully remove the rear sight screw (10-018). The rear sight blade (10-017) holds a very small spring and ball detent (10-084 & 10-013) for the bolt probe. Be careful not to lose these. This pistol I’m working on is missing the spring and ball. 

I used a 1/8-inch (3mm) ball, and a .098 (2.5mm) spring as a replacement.

Replacement springs can be had online, and you can cut them to length, or you can source a 2.5mm spring from under the red button on the smaller Bic lighters, a 3mm spring can be found under the red button of the regular lighters. (I don’t smoke, but they are cheap, and easy to find when you need a spring.)

Older models have a set screw under the rear sight that covers the spring and ball.

Crosman Mark rear sight assy
The rear sight installed, with 2 screws removed.

Crosman Mark rear sight out
The rear sight is out of the pistol. The ball and spring are missing from this gun. The two windage adjustment screws have been left in place. I have removed the elevation adjustment screw and washer (on the left), in preparation for removing the bolt guide.

TIP: I either put the spring and ball on a small magnet and then put them in small pill bottle, or put them together with a piece of clear scotch tape.

Older models have 2 bolt guide screws (10-064) that hold the bolt guide in from either side of the frame, the newer models do not have these — the bolt guide is held in place with the rear sight elevation screw. That is what I’m about to address.

Remove the elevation screw (10-019), and elevation washer (10-040).

Bolt removal

TIP: The bolt has a pin (10-007) that sticks out of one side of the bolt, it is used to lock the bolt in the closed position for firing.  Make sure that the bolt is rotated counterclockwise and pulled rearward fully before trying to remove the assembly, as it will not come out if the bolt is in the closed position. 

Carefully remove the bolt and guide assembly (10-061) out of the rear of the frame, if it seems stuck, check to see if you have all of the screws that could be holding it in, if all of them are out, some heat from a blow dryer may be applied to that area of the frame to help loosen things. 

Crosman Mark bolt and guide
Bolt and bolt guide.

While we are on this subject of loosening things, we do not know the history of most of the pistols we work on, and they can be decades or more old.  Some of the parts may be hard to remove, because the lubricant a previous owner may have used may have solidified, and now have some of the internal parts stuck together quite well. 

Heat is your friend; a blow dryer should be sufficient to soften the goo.  But be careful not to harm your finish with the blow dryer. 

Using either a pair of needle-nosed pliers, or snap-ring pliers, or a spanner wrench, remove the nut (10-004) from the muzzle that holds the outer barrel in place.

As you loosen the front barrel nut the outer barrel (20-163) will start to back away from the frame as it is under spring pressure from the hammer spring. 

Crosman Mark barrel nut and pliers
Needle-nosed pliers double as a spanner wrench for the muzzle nut.

Next, loosen the barrel setscrew (10-006), just ahead of the loading area in the top center of the receiver. It is not necessary to remove it entirely, just loosen it. 

Holding the rear barrel nut (10-005), you can loosen the barrel and remove both it and the nut from the frame.

Hammer spring

Remove the hammer spring (10-023), the cocking knob and shaft (10-059 & 10-021), the hammer (10-022), and the sleeve that the hammer rides in (10-024), out of the front of the frame.

Crosman Mark hammer assembly
The hammer assembly out.

Remove trigger guard

Remove the front trigger guard screw (10-066), and the rear trigger guard pin (10-044). 

TIP: To access the rear roll pin, the safety has to be up in the SAFE position. Drive the pin from the left to the right to avoid putting pressure on the safety lever and possibly damaging it.  The safety does not have to be taken off to reseal the pistol.

This roll pin does not have to be taken out completely, just enough to remove the trigger guard from the frame.  Support the frame in that area with a roll of tape so the pin has a place to go as its being driven out. 

Crosman Mark trigger guard
The trigger guard screw is out (left) and the pistol is sitting on a roll of tape so the rear roll pin can be driven partway out.

Remove the trigger guard (10-012), being careful of the small trigger spring (10-034) at the rear of the trigger guard and trigger. 

Remove the trigger pivot pin (10-032).

Tip: This pin is tapped out from the left side to the right side, you will notice the pin has ridges on one end (arrow), to hold it in the frame, make sure it goes back in the same way it came out.

Crosman Mark trigger spring
The trigger blade has been removed and the trigger spring is left in place.

Crosman Mark trigger and pin
Once the trigger is removed, stick the pin back through to keep it for assembly. Note the knurled end of the trigger pivot pin (arrow) that holds it tight in the frame.

Remove the trigger (10-033) and sear (10-030), paying close attention to its orientation.

Remove the valve

Remove the 2 screws holding the valve in the frame (10-026).

There is a special groove in the valve body (10-025) to help with removal. 

Using a flat-bladed screwdriver with a fairly wide blade and long handle for leverage, place a small wooden dowel, or a second screwdriver across the trigger area to use as a fulcrum, to pry the valve body (10-025) from the frame. I used a pin punch in the pictures.

TIP: Heat may be needed to get this part out, and the rubber seal sometimes sticks to the valve body and frame, so make sure the frame does not have any fragments of the seal in this area before reassembly.

Crosman Mark valve slot
To remove the valve, put something across the frame like the blue pin punch I am showing. Then a screwdriver can be used in the slot (arrow) to pry the valve out of the fame.

Crosman Mark lever valve
A flat-bladed screwdriver is used to pry the valve out of the fame. I’m using a screwdriver with interchangeable bits here.

The valve stem (10-067), and valve spring (10-029) will come out with it. 

Everything we have done to this point this has been just to change a couple of parts in the valve. Let’s look at the valve stem and valve seat I mentioned at the start of this report.

Crosman Mark two valves
The valve stem on the right still has its valve seat. The one on the left has its seat removed for comparison. This is a part most of us will have to purchase — as rebuilding will be beyond our capabilities.

Prep and assembly

Look everything over closely, and clean the parts as necessary, paying close attention the grooves where the o-rings go. Any old rubber or debris there will not let the gun seal. Clean the o-rings grooves with alcohol or your choice of cleaners.

The 4 o-rings in the pistol

Valve body seal is a 014 o-ring. This is one we should replace on this job.

The bolt probe seal is a 006 for the .22 bolt probe, and a 004 for the .177 bolt probe. You have to choose which bolt o-ring to use based on the caliber of your gun. This is the other o-ring we replace on this job.

Piercing cap o-rings

The piercing cap that we rebuilt in the last part of this report has two o-rings. It calls for a 005 o-ring for the pin seal, (I have used a 006 with no issues), and a 113 o-ring for the outer cap seal.

After you clean the valve parts and everything dries, lube and replace the replace the o-ring on the outside of the valve body, insert the valve spring, and valve assembly in the valve body and insert everything into the frame, make sure the port is pointing UP towards the barrel.

TIP: to insure the port is aligned with the transfer port in the frame, I use a sharpie to mark around the valve body lengthways. That way I have a reference line I can center in the trigger area of the frame, and I can also check for vertical from the front of the frame to be sure of centering the port.

Crosman Mark valve with line
I draw an index line on the side and the end of the valve, to tell me where the exhaust port is.

Crosman Mark valve installed
The index line, as seen through the trigger slot when the valve is back inside the gun.

Crosman Mark valve installed front
Here is the rest of the index line as seen from the front of the gun. We will be installing the hammer assembly in the lower tube in front of the valve stem.

Assemble the pistol in the reverse order

TIP: When installing the 2 valve screws, I put blue thread locker on the threads to help prevent any leaks from this area. 

Install the trigger pin, the pin goes in from right to left, with the serrations on the right side to grab the frame. Pay close attention to the orientation of the trigger and sear.

Install the trigger spring, it may be a little fiddly getting it back in the right place, but a dot of silicone grease on one end will hold it in its recess while you align the peg on the trigger into the spring. 

TIP: Hold the trigger in the fired position to keep the trigger spring in place as you install the trigger guard, put the front trigger guard screw in first, it will hold the trigger guard and trigger spring in the right places, as you tap the rear trigger guard roll pin in place.  Support the opposite side of the frame as you tap the roll pin in place, The pistol’s frame is metal, but it is an alloy, and is over 50 years old.

Install the bolt probe o-ring in the groove on the bolt, and reinstall the bolt and guide assembly into the frame.  Remember, on newer pistols the elevation screw goes in the top hole, and on the older models the 2 screws go on the sides. 

Put the rear barrel nut in the loading area, insert the barrel into the frame, and tighten the barrel into the rear barrel nut.  Orient the barrel with the transfer port down, and the small divot up. That’s where the barrel setscrew (10-006) screws into to keep the barrel indexed correctly. 

Crosman Mark barrel divot
This divot accepts the barrel setscrew that keeps the gas port on the other side of the barrel aligned with the valve exhaust port.

Reinstall the hammer sleeve, and hammer, put the cocking knobs through the hole in the hammer, rotate the cocking knob until the tiny hole aligns so the hammer spring extension will go through the hole, this can be seen clearly looking at the rear of the hammer from the front of the gun. 

Reinstall the outer barrel, and the front barrel nut, it just needs to be a little past snug. 

Test the function

Before you install the grips, and before you charge the pistol, put a new CO2 cartridge in, and before you pierce the cap, carefully using a blow dryer, or by setting the pistol out in the direct sun, heat the pistol until it is “toasty warm”.  This raises the pressure in the CO2 cartridge, and softens the seals to help the parts seat properly.  

The design of this pistol is one of the few made where it is ok to be left under pressure. But the decision to leave the gun charged with CO2 is a personal decision, just know there is no face seal for the CO2 cartridge to compress and degrade over time, and the gun being under pressure keeps dust and debris out of the internals.

Congratulations, you have just given your aging Crosman MKI a new lease on life for a few more decades. 

I really love these guns, they are accurate, fun and comfortable to shoot, and in my opinion, have the best trigger of a low cost air pistol ever made.


The basics of shooting: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3
Part 4

This report covers:

  • I can’t use open sights — my eyes are bad!
  • Bad eyes
  • The point
  • Fire Direction Center
  • So what?
  • Eye dominance
  • Sight with either eye
  • What can YOU do?
  • Exercise
  • What’s the point?
  • Pistols and scoped rifles — not such a problem
  • If you really can’t see, use a scope
  • Effect on accuracy?
  • Summary

Today we look at the subject of eyes and eyesight as it relates to the basics of shooting. This is a tough subject and I’m sure there is a lot more than I will address. I’m not an eye doctor, so everything I say today is based on my experience, or on the little research I’ve done.

I can’t use open sights — my eyes are bad!

Yes there are people who absolutely cannot use open sights. I estimate that of those who make this complaint perhaps 5-10 percent of them are correct. Today I want to talk about the others — the ones who just won’t try because they think it’s too difficult.

Bad eyes

In 2010 I was in the hospital for 3-1/2 months with acute pancreatitis. I coded once — a code blue with a crash cart and lots of doctors and other people. My blood pressure was 35 over 25 and they said they were loosing me. I said to somebody there (my eyes were closed and I couldn’t see anyone) that 35 over 25 was pretty low and he responded, “Hey! You shouldn’t be conscious!” Then I was out for three days and when I woke up I hallucinated for the next two weeks. Then they sent me to a different hospital.

At the different hospital I had a young doctor who refused to give me a transfusion when my hemoglobin dipped below 7.0. I told my wife I couldn’t see anything, nor could I concentrate on anything. She found out about the low hemoglobin and the doctor holding back (a nurse told her) and demanded I be given a transfusion. I immediately had two units, followed by a unit per day for the next two days. I also got a different doctor. I was in a teaching hospital and saw 6 young doctors every day, but nobody did much of anything for me. I was fed through a tube in my arm. Reader Kevin knew how bad it was but most readers were kept in the dark.

When I was discharged from that hospital I went home with a feeding tube still in my arm. It remained there for another two months.

The point

My point in telling you all of this is, when I went home, I still could not see very well. My eyes had dehydrated and took six to eight months for them to return to normal. How could I continue writing this blog? My friend Mac helped me a lot in those days but I had to get back to shooting again quick.

I used powerful reading glasses to see the front sight. When I did I was able to shoot again. I might not have been at my peak, but I was certainly okay.

Fortunately I knew something that the people who won’t use open sights apparently don’t believe. You don’t have to see the target very well to hit it! All you need to see clearly is the front sight. Please bear with me on this because there is more to explain before I tie it together for you.

I am aware of this sighting situation more than most folks because I was a 4.2-inch (107mm) mortar platoon leader in the Army. My guns shot at targets 3,000-5,000 meters away — targets the guys at at the guns never saw. Our fire was directed by forward observers (FOs) who watched the target through binoculars that had a mil-reticle in them. They were excellent at determining their range to the target and measuring how far left and right of it (in mils) the mortar shells impacted. And, let me tell you — when a 4.2-inch mortar round explodes, there is no problem seeing it!

Fire Direction Center

My Fire Direction Center (FDC) knew where the FOs were. They also knew where the guns (mortar tubes) were, so when the corrections were called in to the FDC from the FOs, they calculated them from the FOs’ viewpoint, and then shifted their calculations around to the gun’s viewpoint. They then calculated what kind of elevation and windage changes each tube needed to make (each was unique) to hit the target.

Each gun (number one gun through number four gun) would make the traverse and elevation corrections, though only one tube was firing at the time. Once the corrections were made to their gun sights, the gunners looked through their sights and aligned them with their aiming posts that were about 40 feet in front of them. There were lights on the aiming posts for night operations, so they made their vertical crosshair split the light lenses in their centers. Then they leveled their guns until the bubble in the level on the gun’s sight was centered again.

When that tube (the one that was firing) got on target, and that happened within three shots at the max, we conducted a fire mission (we fired for effect) with 2 to 4 tubes — depending on the target. A fire mission is a certain number of shots fired from a certain number of guns. Downrange it is called a barrage. If you are in the place where the shells are landing it looks and feels like the world is blowing up.

One time during a fire mission we dropped a shell down the tank commander’s hatch (we shot at obsolete but real US tanks on the ranges at Grafenwoehr, Germany) and blew the turret off the tank! The division commander, a two-star general, was watching this with my forward observers and was highly pleased.

So what?

Hey, BB, I’m not a mortar tube! Why tell me how they adjust their sights? I shoot pellet guns.

I told you this because you adjust your sights in exactly the same way and for exactly the same reasons, whether you know it or not. The mortar tube’s aiming post is their front sight and it’s about 40 feet away from the gun. Their target may be 5 kilometers away and the gunners can’t even see it. Yet they can hit it consistently because they don’t worry about it. They concentrate on the aiming post. That aiming post is their front sight.

Your eyes are your forward observers and your brain is your fire direction center. It tells your hands how to adjust the front sight (by adjusting the rifle or pistol) to hit the target that SHOULD LOOK BLURRY to you. Nobody can focus on both the front sight and the target. The front sight is where you should focus.

I have taught dozens of people to shoot this way and it ALWAYS works. My best students are women and children who have no prior experience with shooting. That’s because they listen to everything I say, then they try to do it the way I tell them from the start. My worst students are 20 to 40-year-old men who come to me already “knowing” how to shoot. They have so much to unlearn!

Eye dominance

Okay, the front sight issue is out of the way. Now, which is your dominant eye? Keeping both eyes open, look at a spot about 10-15 feet from you. A spot on the wall is good for this. Looking at that spot, hold your hand at arm’s length and stick up your thumb to cover that spot.

Now, wink one eye closed or cover one eye with paper and watch to see whether the thumb seems to move away from the spot. It doesn’t matter which eye you cover. If the spot remains in the same place, uncover that eye and then cover the other eye to see whether your thumb seems to move.

For me the thumb covers the spot when I cover my left eye. But when I cover my right eye the thumb moves to the right. It moves about as far as my eyes are apart. That means my right eye is dominant. If it moves the other way — well, you figure it out.

What if the thumb doesn’t move regardless of which eye is covered? That means both eyes are dominant, and I guess that person can sight with either eye. I seldom encounter that situation, though I know it does exist.

Sight with either eye

While I am right-eye dominant, I can sight with my left eye. It doesn’t feel comfortable, but I can do it. However, there are people who find that incredibly difficult to do. My wife, Edith was one who couldn’t do it. So airgun maker Gary Barnes made a special offset scope mount that allowed her to shoot a Barnes Ranger precharged pneumatic.

barnes ranger
Gary Barnes made this special offset scope mount so Edith could sight with her left eye while shooting right-handed.Those two outriggers adjust independently and the scope rings swivel to align with the scope tube in any orientation.

Besides the trajectory correction she also had to make a correction for the sideways offset of the scope. So, shooting at different ranges was a challenge. But BRV was a bullseye game that was always shot at the same distance, so that’s where she competed.

edith shooting
Edith competed in BRV with a .177 Barnes Ranger PCP rifle.

What can YOU do?

You have options if you are what is colloquially known as odd-eyed dominant — a right-handed person with left-eye dominance and vice-versa. First, you might be able to learn to shoot with the other eye. I can do it, though I don’t like it. But when my left or non-dominant eye looks at sights I find it best to cover the dominant eye somehow. And I said cover — not close the eye by winking. I have an exercise to show you why winking your non-sighting eye doesn’t work.


Poke a hole through a piece of stiff paper or card stock. Let’s make it around 1/4-inch or 6.35 millimeters in diameter. That’s roughly. Don’t sweat the measurements! I used the awl on my Swiss Army knife to poke the hole and it’s not very round.

hole in card
The hole doesn’t have to be precise. Even something as rough as this will work.

Now, keep both eyes open and cover your non-sighting eye. Bring the hole in the card up to your other eye about 3/4-inches away and the hole will appear to remain fully open. Then, close your other eye by winking and watch the hole shrink in size. The edges become blurry and you notice them closing in. The more you wink the smaller the hole becomes. That is what happens when you sight with one eye and close the other one by winking! Don’t do it because it makes the light through the peephole or through the rear sight notch decrease dramatically. Use an eye patch if you must, but keep both eyes open.

What’s the point?

The point is — don’t close your other eye when sighting. Train yourself to leave it open, because closing it by winking or squinting just reduces the amount of light that comes through your sighting eye.

Okay, that was option one — use the other eye. Option two is to shoot from the other side, i.e. a right-handed person shooting left-handed. I find it easier to do that with a rifle than a pistol. Some folks have no trouble doing it either way with both rifles and pistols. Those folks have already figured all of this out and they are waiting for the rest of us to catch up.

The last thing I recommend is getting a special gunstock or sights or a trick scope mount like I show above. They are just as difficult to live with as the problem they are designed to correct.

Pistols and scoped rifles — not such a problem

With pistols or when shooting rifles with scopes this is far less of a problem. Close (I say cover up) the eye not being used and just use the other one. Action pistol champion Rob Leatham demonstrates this. However, notice when he switched to sighting with his non-dominant left eye it took him longer to get on target.

Shotguns are a different matter because they are not shot with sights when wingshooting. Fortunately for me this is an airgun blog and I don’t have to go there.

If you really can’t see, use a scope

I have written this report for the shooters who use poor vision as an excuse for using scopes all the time. But I do recognize there are folks who have to use scopes because they really can’t see the sights. For them there are very few options. Fortunately scopes today have reached a high level of refinement while their prices have dropped to reasonable levels.

Effect on accuracy?

This is the second part of today’s question. How does eye dominance play into accuracy. The answer is simple. It plays to the extent that the shooter allows it to. In other words, a determined shooter can shoot well with either eye. With practice comes familiarity and with familiarity comes skill. However, if the shooter constantly fights it, the problem will become an exercise in developing excuses for why he can’t shoot.


There — five parts of a report I initially thought would be over in one. Reader Bill, see what you made me do?

The basics of shooting: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2

This report covers:

  • Accuracy from gross to fine
  • Rough airguns
  • Smooth airguns
  • Trigger
  • Cleaning the barrel
  • Sight picture training
  • The triangulation system
  • Making a triangulation sighting bar
  • Conduct of the exercise
  • A simpler, faster way to begin
  • Style of the sights doesn’t matter
  • The results you want
  • Summary

Wow! I started this series for one reader but it seems like many of you are enjoying it. I have a lot to cover today, and part of that comes from your comments. So, thanks! I want to begin where we left off in Part 2.

Accuracy from gross to fine

In Parts One and Two we looked at the things affecting accuracy. They started with major things like sights and rifling that caused gross increases in accuracy. Then we looked at things that made smaller improvements — things like the hold, breathing and trigger control.

We have gotten to the point of refinement where any further improvements will be very small, but many shooters are not using the things we have already discussed. We’ll start with the hold, but we will focus on the airgun rather than the shooter.

Rough airguns

There is a class of airgun that is quite rough in operation and it’s nearly impossible to be accurate with one. The breakbarrel springer that shoots at super-high velocity, say 1,200 to 1,400 f.p.s. in .177 caliber, is a good example, however you will find air rifles like this in every caliber. These guns almost always operate roughly. They are hard to cock and vibrate and recoil a lot when they fire. No matter how potentially accurate their barrels might be, it is practically impossible to shoot such airguns well. They come from China, Spain and Turkey, but in the past have also come from Germany and the United Kingdom.

I tested a Turkish-made Webley Patriot in 2007 and found it to be adequately accurate, though a lot of special hold technique had to be used. By that I mean the artillery hold. Resting the same rifle on a sandbag tripled the size of the group at 25 yards.

More recently I tested the Hatsan 135 QE Vortex .30-caliber pellet rifle and found it very accurate at 25 yards but far less so at 50 yards. However — and this plays into what I’m saying about the roughness of the powerplant — I also shot the same rifle that Rich Shar had modified and tuned for smoothness and I found his to be very accurate at the longer distances. We shot it out to around 40 yards at the 2018 Pyramyd Air Cup. Now, besides tuning the powerplant to be incredibly smooth, Rich has also replaced the Hatsan barrel with a custom barrel. So that test wasn’t a one-for-one test. But I think it does support my point about smooth airguns shooting better.

Smooth airguns

Contrast what I have just said with air rifles that shoot smoothly, and the Air Arms TX200 Mark III is the poster child of smooth-shooting springers. The TX isn’t weak. Mine shoots a 7.9-grain Crosman Premier pellet at over 950 f.p.s. When I first got it about 20 years ago it shot that same pellet at 875 f.p.s. and all the increase in speed has come from just shooting the rifle. And, talk about smooth? It’s the closest new spring gun you can find to shooting a precharged rifle!

Remember how I raved about the ASP20 when it first came out? That’s another spring-piston rifle that has been made very smooth, only that one has a gas piston that is usually quite harsh. But, through engineering, Sig managed to smooth out the action and make a 23 foot-pound (in .22 caliber) spring rifle. So, shooting smoothly is one answer to accuracy.

All of this discussion centers on the subject of hold, only this time it’s all on the side of the rifle rather than the shooter. But even with an accurate rifle, the shooter can hold incorrectly and lose much of the potential. We have discussed using the artillery hold that works for nearly all recoiling spring-piston air rifles. Until shooters learn about it they will never get the kind of accuracy we see.

The same holds true for the shooters who don’t control their breathing. The sport of biathlon (cross-country skiing and marksmanship) is structured around extreme exercise to get the heart rate and breathing outside comfortable levels and then force shooters to shoot accurately.


I haven’t said as much about the effects of the trigger, but they are just as real. We don’t celebrate the Weihrauch Rekord trigger for nothing! Even a precharged airgun can lose some accuracy if the trigger is either too rough or too vague. A 5-pound trigger that breaks consistently is better for accuracy than a 5-ounce trigger that has no distinct second stage. In recent tests you read where I praised the triggers on both the Air Arms S510 Ultimate Sporter and the FX Dreamlite. Of course both of these are high-end air rifles, but the TX200 Mark III sells for half as much or less, and the ASP20 is less than one-third the price. Good triggers don’t have to cost a lot, but bad triggers can spoil the whole shooting experience.

Cleaning the barrel

I don’t like cleaning airgun barrels because I think it’s not usually necessary, but there is an instance when it is. When the accuracy of a given gun deteriorates, you should clean the barrel. And I mean clean it aggressively with JB Non-Embedding Bore Cleaning Compound on a brass or bronze brush.

I’m not just talking about barrels that have been made dirty from shooting. An airgun barrel will ALWAYS have black stuff inside because it’s the anti-oxidant compound that’s on most pellets. It’s not actually dirt and it gets pushed out of the bore with every shot, while new stuff is deposited. Don’t worry about that stuff. I’m talking about lead fouling. Lead from pellets will smear inside the bore and degrade accuracy. That’s what the JB compounds gets rid of.

When your airgun starts to become noticeably less accurate it’s time to scrub the bore with JB compound. Some world-class target shooters clean their barrels this way once each year. I seldom do it and I have guns with over 10,000 shots since they were last cleaned.

I have also seen improvement when the barrels of certain brand new airguns were cleaned in this way. One of my jobs when I worked at AirForce Airguns was to clean every barrel by hand in the way I have just described. These are all premium Lothar Walther barrels but after they were delivered to us we ground their outsides to a precise dimension, and we had them all blued. Cleaning was the final step before they were assembled into airguns. I am talking about hand-cleaning hundreds of barrels at a time — a  job that could easily take up most of an 8-hour day! I feel quite certain that other makers of premium airguns like Air Arms, FX, Daystate and others do the same thing.

Now I’ll talk about a major training tool for the novice shooter. It’s how to use the sights!

Sight picture training

For new shooters, some training with the sight picture establishes whether or not they understand how the sights work. Here is a wonderful way to teach people how to use the sights.

The triangulation system

When I was a youngster, my mother enrolled me in an NRA-run course that taught me how to shoot. This was in the late 1950s, and the techniques used to teach us back then were those that had been popular both before and during World War II. I’ve researched both the modern U.S. Army and Marine Corps marksmanship syllabi and find that what I’m about to show you is, unfortunately, no longer taught — but it should be! Today’s lesson could turn out to be the most valuable teaching technique you ever learn for training new shooters.

We’re going to teach the new shooter how to use sights through a method called triangulation. Although we’ll be using aperture sights that are the easiest to learn and the most precise to use, any type of non-optical sight may be taught by this method. Read everything before asking any questions. This method will immediately reveal whether a student understands how to use sights, plus it will show the student’s level of skill in sighting — all without the use of a rifle.

Making a triangulation sighting bar

You can make a simple training aid to teach the student how to use the sights. It consists of a straight bar with open “sights” on each end. An 18″ strip of wood will suffice for the bar, and you can fashion the “sights” from paper index cards. If you’re the coach of a shooting club and plan to teach a lot of kids, it might be worth the effort to mount real sights to the bar, though that isn’t necessary. Simple card-stock sights taped to the bar as shown in the drawings will work great. If you cannot find a piece of wood to use for the bar, a long ruler works well as a substitute. The dimensions of this training aid are not precise and critical, as long as it’s made reasonably close to what’s described here.

Triangulation bar

Poke a small hole through the rear “sight” for the student to peer through. The front “sight” is just a square post. Fasten both front and rear sights to the bar so they cannot move during the exercise, as repeatability is important. Place the sighting bar on a box so the student can use the sights without touching or moving them.

The instructor stands or sits 33 feet away and holds a black bullseye target against a large white piece of paper that’s attached to the wall or to a large box under his seat. In the center of the black bullseye on the target, a small hole has been made for a lead pencil to poke through and mark the white background paper.

Training room
six o-clock hold

Conduct of the exercise

The student looks through the sighting bar and tells the instructor how to move the bullseye target until it’s positioned perfectly against his sights for a 6 o’clock hold. It’s important that the sighting bar does not move during the exercise — only the target, as adjusted by the instructor. When the sight picture looks right, the student tells the instructor to mark the target and the instructor makes a mark on the white background paper by pressing his pencil through the hole in the center of the target.

A simpler, faster way to begin

You can avoid making the sighting bar if you want to by simply using the rifle itself. Simply rest it so the student can see through the sights without touching or moving the rifle. This will be more difficult because the stock gets in the way, which is why the bar was created, but it is possible. Once again, you don’t want that rifle to move.

Many people don’t like the idea of being downrange with a rifle pointed at them, and the sighting bar makes it unnecessary. I think the sighting bar is a much better training aid that takes only a few minutes to create.

Style of the sights doesn’t matter

Don’t worry if your rifle’s sights don’t look like the sights I’ve shown here. You can make them any kind of sight you desire. Just cut them out of card stock and color them black to help the student define the sight picture. If you plan to use open sights with a rear notch, be sure to allow enough room on the bar behind the rear sight so it appears reasonably sharp to the student when aligned with the front sight. And remember to tell the student that the front sight is what they must focus on — not the rear sight and not the target. Both the rear sight and the target should appear slightly out of focus when they sight correctly.

I have wanted to share this technique with you readers for years, but I held back because I felt it might be too difficult to follow. I hope this report has made it clear and that this exercise helps both you and your students learn how to use open sights as it once helped me. One week after completing this exercise successfully, I was shooting five-shot, dime-sized groups at 50 feet from the prone position, which was the first position the NRA taught.

Repeat this exercise three times and there will be three pencil marks on the white background paper. The closer these marks are to each other, the better the student has adjusted his sights. This gives both the student and the instructor an excellent idea of how well the student understands the sight picture.

Pencil marks

The results you want

What you are looking for is three dots on the background paper in the form of a triangle. A good result is if the dots are all within one inch of each other. Don’t be surprised if they are within one-half-inch of each other. The closer they are, the better and more precise the student is seeing the sight picture.

But if the dots are several inches apart, the student is not yet seeing the sight picture correctly. They may not understand all that is required of them in the exercise, or they may not appreciate the precision they are expected to achieve. Also, this could be an indication of a vision problem.

Once you determine the problem(s), you can run the exercise again until they get it right. When the student can place three dots close to each other, they will instinctively know how the rifle sights should look.


This report grew long because of explaining the triangulation exercise. I didn’t address the problems of different ammo, nor of the difference that airguns bring to the accuracy table. And there is also the problem of how close airgunners are to their targets. So there is more to come. If you have additional things for me to address, please let me know.

2019 Pyramyd Air Cup: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

Vendor's Row
There were more vendors than ever this year! They were arranged on streets under pop-ups.

This report covers:

  • Big
  • Downrange
  • Down to the public ranges
  • Repeating crossbow pistol
  • American Airgunner
  • Air-air-air!
  • Gee whiz!
  • Summary


I knew it was going to be good when I first saw it driving up. I saw rows of colorful tents arranged like a country fair. They turned out to be several streets with vendors on each side, and as the morning advanced they were filled with representatives from their companies. We had been told that the Pyramyd Air Cup site was bigger this year and I have to report that it certainly was!

In fact, on day two I was shown the other side of the facility and discovered that what I was on was the small side. The real facility is several times larger than what I had seen on the first day. And that other side includes a clubhouse/event center that has an indoor swimming pool! The banquet Saturday evening was held in that facility.

Camping sites were in the woods on this side of the road and equipped with everything a RV or tent camper could desire. You guys who camped there please correct me if I’m wrong, but I saw hundreds of well-equipped hookups.

The Cup started on a Friday with competitors shooting in both the inaugural benchrest competition and the Gunslynger that has run for many years. There were a large number of competitors on the line when I arrived at 8:30.

Benchrest briefing
I’m looking at half of the benchrest competitors. The other half is behind me. This is the pre-match safety briefing.


The benchrest targets were 100 yards downrange and the wind was blowing 10+ m.p.h. with frequent gusting. Everyone was having their pellets blown to the left — sometimes by several inches.

The range flags were blowing right to left at 100 yards!


I stopped by the Leapers booth and saw a new 4-16 scope with improved light transmission. It has an etched-glass reticle and the adjustment knobs are calibrated in the same increments as the reticle lines. This makes adjusting the scope easier, as no mental conversion is required. They are sending one to me to test for you, and I can’t wait. Did I mention that it is very compact — only a little longer than a Bug Buster.

I also saw a new high-tech bipod that I will soon be reviewing for you. This one is really slick and after my experiment with the Daisy Buck a few weeks back, I’m excited to try it

Down to the public ranges

This venue is huge! I bet the public shooting ranges are a quarter-mile from the competition and Vendors’ Row. Pyramyd Air had several range carts to ferry people, so I hopped on one and went down to the public ranges. These are where you can try many different airguns that Pyramyrd Air and some of the other vendors provide. The also had a sales office down there and everything they sell was marked down by 20 percent with free shipping! But I also saw some things that hadn’t yet been seen by the public.

Repeating crossbow pistol

The first new thing was a 6-shot repeating crossbow pistol from Europe. It is way cool and so new that it doesn’t have a name yet, but it sells in Europe under the name Steambow. I was surprised by how accurate it is and also by the power — 16+ foot-pounds!

This crossbow pistol is every bit as much fun as it appears in this picture. BB wants to to test one! Heck — he wants to own one!

The real news with the Steambow, however, is not the pistol. There is also a full-sized crossbow that is cocked buy CO2 pressure! I saw it cocked and shot several times, and I even shot it myself a couple times. It is supposed to be highly accurate. I don’t know how long we will have to wait to see this reach the market but I can tell you that Pyramyd Air is working on it as fast as possible.

big Steambow
The full-sized bow is cocked via CO2 pressure. This is a bow that will compete with top-quality crossbows like the Sub-1 and the Ravin.

There is more than one version of the full-sized bow coming to market, so there will be more to say as the details are refined.

American Airgunner

The American Airgunner television show was at the Cup and host Rossi Morreale was competing in several events. When he wasn’t doing that he was interviewing people all around the event. You’ll get to see parts of the Cup online and in next year’s show.


The guns at the Cup run on air and Pyramyd had several of their compressors going all the time, filling large tanks. Even so, they were hard-pressed to keep up with the demands of so many shooters.

These Air Venturi compressors were going most of the day, filling dozens of large carbon fiber tanks.

Gee whiz!

I was at the Pyramyd Air support tent, talking to Gene Salvino, whom many of you know, when he showed me something wonderful. Gene works in the Tech department fixing airguns, and he tells me his biggest problem is fixing the guns that have pellets stuck in their barrels. He told me tales of 16 and even 32 pellets jammed in the bore of thousand-dollar PCPs!

To get them out he has created an ingenious tool that I want to show you. He took a steel Dewey cleaning rod that was broken and he threaded one end with a 6-32 thread behind a sharp point. He chucks the other end of the rod in an electric drill and goes in usually from the muzzle, drilling into the head of each stuck pellet in turn. The rifle is in a padded vise while he’s doing this.

He says you can hear a change in the drill motor when the rod has penetrated the head of a pellet. He then pulls on the drill chuck and that pellet comes right out! Keep it up until the bore is clean.

Gene Salvino passes this tool along to you readers with his complements. Make the rod as long as possible, but he also has a shorter one for jobs when the pellets are closer to the muzzle — to keep the rod from flopping around inside the bore.


This was just the first day of the Cup and I already saw enough for several blogs. On Saturday I taught some classes to the public on how to mount a scope and how to sight one in after it is mounted.

There was more to see, more to do, more contests to enter and more vendors to talk to this year. The new venue is much larger and more accommodating to the needs of the event. The event now has plenty of room to grow. They completely shut down all firearms activity for this weekend and we had the full run of the place.

I will report on the Cup again this week, but I’ll give it a couple days.