Umarex Air Javelin airbow: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Umarex Air JavelinThe Air Javelin from Umarex.

Part 1
Part 2
Part 3

This report covers:

  • More to test
  • What are the holes for?
  • Remove the old 88-gram cartridge
  • Lots of gas!
  • Install the adaptor
  • Cock the gun!
  • Don’t do as BB does!
  • Adjust the dot sight up
  • Discussion
  • Summary

Today I shoot the Umarex Air Javelin with a dot sight optic. My UTG Reflex Micro  Dot was mounted elsewhere so I mounted a Tasco Pro Point red dot sight. 

Air Javelin dot sight
The Air Javelin accepted the Tasco Pro Point without a problem.

More to test

I didn’t tell you this but I asked Umarex to send me a 12-gram CO2 adapter so I could test the AJ with 12-gram cartridges. Some readers had asked about that possibility and since Pyramyd Air doesn’t carry the adapter, I went straight to Umarex.

Air Javelin 12-gram adapter
Several Umarex airguns including the Air Javelin use this adapter that switches the power source from 88/90-gram CO2 cartridges to 12-gram cartridges.

Let’s look at how it works. One end has an end cap that unscrews to accept the two 12-gram cartridges. The other end is treaded to screw into whatever airgun you install it on.

Air Javelin adapter description
The adapter has an end cap (arrow) that comes off to insert the CO2 cartridges, and threads on the other end to screw into the airgun. The holes are for moving the end cap when pressure holds it tight.

The two cartridges go into the adapter nose to nose. The piercing end of the first cartridge goes in first and the piercing end (small flat end) of the second cartridge is left up at the top, where the pin in the cap can pierce it. There is a spring-loaded winding tab on the cap. The spring holds the tab flat against the cap until you need it.

Air Javelin adapter cap off
The adapter cap has been unscrewed.

No directions for use came with the adaptor but it is pretty easy to figure out. I unscrewed the end cap piercing screw as far as it would go before dropping two cartridges inside. And I dropped in 5 drops of Crosman Pellgunoil before inserting the first cartridge. Then I put more Pellgunoil on the tip of the second cartridge.

Air Javelin cap screw
Here you see the cap screw (bottom) unscrewed as far as it will go.

What are the holes for?

If you ask what the holes in the sides of the end cap are for you haven’t yet encountered a gas gun with so much pressure that it wouldn’t let go of the end cap. This used to be a real problem in the 1950s and ’60s when improper o-ring material would swell from the gas and no let go of the end cap for hours after the gun was empty. With modern materials there is no more problem, unless the gas pressure inside the adapter is still high. This is not a large problem; it’s more of a convenience.

As you can see, I unscrew the piercing screw on the end cap as far as it will go, then screw the end cap down as far as it will go. Now I pick up the spring-loaded tab and start screwing the piercing screw in. That one screw is piercing both cartridges. It pushes the bottom cartridge down on the internal piercing pin inside the adapter as well as screwing in the piercing pin in the end cap. So I run it in as far as it will go. I heard no gas escape when I did this, but just to make certain the piercing pins were out of the way of the gas, I unscrewed the tab about a turn.

Remove the old 88-gram cartridge

Before the adaptor could be installed I first had to remove the previous 88-gram CO2 cartridge that was in the AJ. I didn’t know for sure but I calculated there were around 20 shots on it. We learned in Part 1 that the AJ has up to 30 good shots on one 88-gram cartridge. The last shots will send arrows out at just under 200 f.p.s. while the first shots have them going over 300 f.p.s. I will have more to tell you and show you later in this report, but for now you need to know that I was removing a cartridge that had a good 10 shots remaining inside. I had to do it to get a shot count from the two 12-gram CO2 cartridges in the adapter I’m about to install.

Lots of gas!

I will say this. Once you slowly unscrew the CO2 cartridge it comes to a point when the remaining gas is no longer sealed and starts hissing out. That lasted a long time — several minutes at least. I also dry-fired the AJ about 10 times as it was loosing gas to speed up the process. In the end the last gas hissed out and the old cartridge could be removed. The gun was now ready for the adapter.

Install the adaptor

The adaptor just screws into the gun where the CO2 tank was. Remember I put Pellgunoil inside when the cartridges were pierced, so that gets blown into the AJ to get on all the internal seals. BUT…!

Cock the gun!

Umarex tells you not to cock the gun when installing a new cartridge and I expect they also mean this adaptor. That is obviously a safety issue. But the adaptor holds two 12-gram cartridges that have limited gas. So I screwed the adaptor in, and when the hissing began I cocked the AJ and stopped it instantly.

Air Javelin adapter in
The adaptor fits in the AJ just like an 88-gram CO2 cartridge. This photo was very important later in the test!

Don’t do as BB does!

This is an object lesson. Some of you think I am modest, but the truth is — I am often that bad example your mother warned you not to follow! I set up the target bag in my back yard about 10 meters from the shooting bench. Yes that’s pretty far but I hadn’t shot the AJ in two months and my last recollection was one of great accuracy. It really was accurate last time — what could go wrong? I held the red dot in the center of the target that was taped to the bag and fired the first arrow. But I couldn’t tell where it went. It wasn’t anywhere on the bag! Oh, oh!

I looked in the grass all around and under the bag for signs of the arrow and then in the wooden fence between my property and my neighbors. Nothing. So I dragged the bag back to 5 meters and shot again. This is where I should have placed the bag to begin with.

Adjust the dot sight up

This time the arrow hit the bag, just below the bottom of the target paper. My previous shot had been taken at twice the distance, so the lost arrow is definitely somewhere in my lawn at something less than 10 meters. I searched for another 10 minutes for that first arrow with no luck. Umarex had only sent me three arrows with the AJ, and now I was down to just two. I adjusted the elevation up considerably and shot again.

Shot three hit a half-inch or less from shot two. It was on the bag but still below the target paper. From the looks of it (it was on an angle in the bag), it may well have hit the back of the second arrow— something I would discover in a little bit. Now I knew I was on the target so I cranked in a whole lot more elevation and moved the bag out to 15 meters.

Then I let fly with shot number four. This time the arrow hit the bottom of the 6-ring, almost touching the bullseye at 6 o’clock. Wow! I pulled the arrow out and moved the target bag out to 20 meters.

That shot had looked so good that I fired my second shot (number five on the CO2 adaptor). It hit the target about 3/4-inches below the last one. I needed to watch out or I would Robin Hood my two remaining arrows.

The last test in Part 3 demonstrated that the AJ is very accurate at this distance, so I felt confident it would not be a problem. However — remember that arrow that may have been hit in the back? I knew that I would nail the target in line with the center of the target and with luck I’d be inside the bull. No such luck! This time I heard a sickening sound of the arrow hitting the fence behind the bag. I have never missed the bag before this shot and was surprised I missed it this time. I found the arrow that had gone 4 feet wide to the left and was halfway through the fence.

When I pulled that arrow out of the fence I examined it to see why it had gone so wide. Right away I saw it. The end of the arrow is blown out on one side. I think I did hit the back of this arrow earlier and now I was rewarded with a wild shot. When I enlarged the pictures of all three arrows that was taken before the test started I saw that none were damaged this way. That is what I meant by that earlier picture being so fortuitous.

Air Javelin arrow end
The end of the AJ arrow that went so wide at 20 yards was broken out on one side — causing the arrow to veer to the side as it came off the end of the air tube. This arrow was probably hit in the rear on shot number three.

Air Javelin arrows
I enhanced this earlier photo to show there was no damage to any of the three arrows at the start of this test.

For safety’s sake I moved the target bag back to 15 meters and fired my one remaining arrow three more times — shots 7, 8 and 9. Shot 7 hit the target at the bottom center of the largest ring in the white. I had to pull the arrow to shoot shot 8 and it hit the target about 3/4-inches below and to the right of shot 7. On this shot I noticed a lot of time between the shot and the arrow hitting the bag.

Air Javelin arrows shot 8
Shot 8 at 15 meters hit below and to the right of shot 7. I could hear that this arrow was slower.

I pulled the arrow and fired one more time. This time there was a definite slowing of the arrow and it hit at the bottom of the paper, a little more than an inch below shot 8.

Air Javelin arrows shot 9
Shot 9 hit the target a little more than an inch below shot 8.


Based on this test I can say that two 12-gram CO2 cartridges give you about 8 good shots. They are not all the same speed, but I believe they all fall within the velocity spread of the 30 good shots you get from an 88-gram cartridge. Analyzing the costs tells me you get 8 good shots for about $1.00 with two 12-gram cartridges, and 30 good shots for about $8.00 with one 88-gram cartridge. The advantage of the adapter is shots that cost less. The advantage of the 88-gram cartridge is a lot more shots per cartridge. The velocity of the shots is the same because CO2 varies its pressure due to temperature. Volume is not a factor in pressure.There is no easy way to increase or decrease that pressure — certainly not one that’s available to the field.

The second thing I would tell you is to always examine your arrows just before loading them. I didn’t and only through a fortunate photograph was I able to determine that an arrow had been damaged during this test. A damaged arrow flies erratically and is too risky to shoot.

One last comment is that I need to jack up the rear of the dot sight for the next test. I had to apply too much elevation to get the arrows near to the aim point.


I’m still very impressed by the Air Javelin. Even with the challenges of today’s test, which in retrospect were all mine, the AJ held its own. When it is given half a chance it places its arrows close together at the distances I have been testing.

The CO2 adapter performs as well as many expected. I was surprised by the number of good shots we got in today’s test. And it is very easy to set up and use.

Hopefully we will see the AJ at least once more, and this time with more arrows and no sighting problems.

Slavia 618 breakbarrel air rifle: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Slavia 618
Slavia 618.

Part 1

History of airguns

This report covers:

  • Before the test
  • RWS Basic
  • How does it shoot?
  • Crosman Premier Light
  • Discussion 1
  • Re-test with the “new” seal
  • Basic test 2
  • Premier Light test 2
  • Discussion 2
  • Cocking effort and trigger pull
  • Summary

Today I test the velocity of the Slavia 618. You will recall that I have two of these rifles and one seems to be performing well. That’s the one I’ll test. The other rifle I will rebuild, but we will look at that in a separate report some time in the future.

Before the test

This rifle has a leather breech seal which is indicative of a leather piston seal, as well. So I dropped about 5 drops of Crosman Pellgunoil down the barrel and stood the rifle on its butt for a few days to let the oil run down into the compression chamber and soak into the leather. It also soaks into the breech seal as it passes, softening it up so it can do the job it was designed to do. That should get the rifle into the best possible condition for a velocity test.

Slavia 618 old breech seal
The old leather breech seal was dead flat. I oiled it but shot the rifle with it in place.

RWS Basic

The first pellet I tested was the 7-grain RWS Basic wadcutter. They averaged 410 f.p.s. from this rifle. The spread went from a low of 395 to a high of 427, so a difference of 32 f.p.s. At the average velocity this pellet developed 2.61 foot-pounds at the muzzle. As ugly as it looks, it is a shooter!

How does it shoot?

The rifle shoots calmly without vibration. It’s rather pleasant to shoot, actually. It’s light and quick and the trigger feels decently crisp. It cocks with a light pull on the barrel and when the sear catches its crisp and positive.

Crosman Premier Light

Now it was time to test the rifle with a heavier pellet. I selected the 7.9-grain Crosman Premier Light for this. Premier Lights averaged 392 f.p.s. with a 70 f.p.s. spread from 361 to 411 f.p.s. That’s pretty crazy! At the average velocity this pellet generated 2.7 foot-pounds at the muzzle.

Discussion 1

This 618 is performing well for its age. But that flat breech seal had me wondering if there was more performance that was being robbed by loss of compressed air.  So I did an old spring-gunner’s trick. I removed the leather seal.

Slavia 618 breech seal out
The old leather seal has been removed from the 618’s breech.

Slavia 618 leather breech seal
The leather seal is pretty decrepit!

And here is the trick. Leather seals can look horrible and still be made to do a good job of sealing the breech. I put two paper shims under the seal, flipped it over so the face that was exposed was more uniform and reinstalled it. Now the seal is more uniform and stands taller.

Slavia 618 shimmed breech seal
The inverted and shimmed breech seal now stands taller and is more uniform.

Re-test with the “new” seal

I felt it would be good to test the 618 again with the new seal, now that it was taller and more uniform.  I will test with the same two pellets.

Basic test 2

This time RWS Basic pellets averaged 433 f.p.s. — a gain of 23 f.p.s. The spread this time went from 429 to 440 — a difference of 11 f.p.s. That compares to the spread of 32 f.p.s in the first test. At the average velocity this pellet now produces 2.91 foot-pounds. Refreshing the breech seal has increased velocity and cut the variation by two thirds. I’d call that a result!

Premier Light test 2

Premier lights averaged 405 f.p.s. this time. That’s a gain of 13 f.p.s. The spread went from 383 to 415 f.p.s. — a difference of 32 f.p.s. That compares favorably to the 70 f.p.s. difference in the first test, though I will say that the Premier pellet does not seem suited for this air rifle, no matter how well it shoots. Premiers now develop 2.88 foot-pounds at the muzzle.

Discussion 2

My point in doing all of this is that this Slavia 618 seems to be in fine shape for an accuracy test. No, it’s not recently rebuilt, but it out-performs other 618s that have been. That is what a little oil can do for a leather piston seal. I have seen leather seals that could have been as much as a century old revived by oiling. I have also seen them crumble into a pile of dust from dry rot, so their past does play a big part in whether or not they can be brought back.

Of course the seal trick is just that — a trick. The breech seal should be replaced before long.

The rear sight on this rifle is the one that was bent to the left. I will swap it for the rear sight on the other rifle that seems to be okay. And then I will conduct the accuracy test.

Cocking effort and trigger pull

This 618 requires 12 pounds to cock it. That’s light enough for small children. The single-stage trigger pull on this rifle measures 3 lbs. 5 oz. While that doesn’t sound that light, the break is clean and crisp and I find it delightful.


We have a good one here. It wants to shoot lightweight pure lead pellets and I bet it can shoot them well. We shall see!

Beeman R10: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Beeman R10
Beeman R10.

Part 1
Part 2

History of airguns

This report covers:

  • Recap
  • The initial test
  • Today’s test — the firing cycle
  • JSB Exact 8.44-grain
  • How I set up the Vortek kit
  • Air Arms Falcon
  • RWS Superdome
  • Cocking effort
  • Summary

Today is the day we find out what the Vortek PG3 SHO tune has done for the Beeman R10 I’m testing.


I received the rifle from a reader who wanted a rifle that had a tune done by me. I will tell all of you now that I am not an airgun tuner. I tune some of my own guns from time to time, but I don’t do it as a service. And there is absolutely nothing special about any tune I have done. This report is more a testimony of what the Vortek kit can do than it has anything to do with me.

The reader and I both agreed that a smooth-shooting air rifle was preferable to the last f.p.s. in velocity. So smoothness was what I was after, and nothing more, as long as the rifle performed within reasonable parameters.

I had installed one Vortek PG3 kit previously, but like I told you previously I applied Tune in a Tube to that mainspring — to make the powerplant as smooth as it could possibly be. This time, however, I decided to tune the gun the way Vortek recommended, to see if their kit was as smooth as they claimed. So all I used was the Vortek grease that came with the kit. Gene Salvino says it is slicker than TIAT and it is certainly less viscous. It would be up to the tolerances of the Vortek kit to eliminate vibration.

I told you that when the piston was installed it moves inside the spring tube with resistance. Several readers advised me to trim the piston seal down a little to realize more velocity. But as I have explained — velocity is not what I am after. I want smoothness, and a looser piston seal could well allow a little vibration back into the rifle.

The initial test

After receiving the rifle I tested it with the same JSB Exact 8.44-grain domed pellet that the owner had tested it with. He recorded a velocity of 847 f.p.s. My ten shots averaged around 815 f.p.s except for the last shot when the cocking link disconnected with the piston. So my chronograph reads about 30 f.p.s. slower than the chronograph owned by rifle’s owner. That sets us up for understanding today’s test.

Today’s test — the firing cycle

The firing cycle of the rifle before the tune had some vibration on every shot. When I took the mainspring out we saw it was canted and starting to fail. That was where much of the vibration came from.

The rifle now fires with zero vibration, which is exactly the result I was seeking. In fact I said this was as good a tune as I have even done. Only my Beeman R1 with the custom Mag 80 LazaGlide kit that I installed about 22 years ago was as smooth! Therefore, I did something I say I try never to do. I pulled out my HW85 rifle (the same model as the Beeman R10) that Brian Enoch tuned years ago. This is the rifle I bought from him just based on how smooth it shoots.

That rifle is a .22 so I can’t compare the performance but I can compare the shot cycle. Both rifles are equally smooth but Bryan’s tune does something this one doesn’t. At the end of the shot cycle with the R10 I just tuned there is a very tiny forward bump, when the piston comes to a stop at the end of the stroke. Bryan managed to prolong the timing of that bump in the HW 85 he tuned, so it feels like slightly less. But as I said before — this Vortek kit gives you a $400 tune for $90 if you do the work.

JSB Exact 8.44-grain 

First to be tested was the 8.44-grain JSB Exact. That would tell us what this Vortek tune has accomplished.

Ten pellets averaged 818 f.p.s. through the chronograph, so the kit has maintained the same power as the factory powerplant. The velocity spread was 11 f.p.s., from 809 to 823 f.p.s.. That’s a little better than what we saw with the factory tune before the cocking link disconnected. It varied by 19 f.p.s. from 806 to 825 f.p.s. At the average velocity this pellet now generates 12.54 foot-pounds at the muzzle.

We know that the owner’s chronograph is recording velocities higher than mine. I think we can expect him to see a velocity of about 850 f.p.s. from this pellet when he gets the rifle back.

How I set up the Vortek kit

Now I will tell you something I purposely left out of Part 2. The Vortek kit has a forward spring guide  (I call it a tophat) that has three positions for the end of the spring. Think of them as low-, medium- and high-power settings, though the differences aren’t that great. In the Air Arms Pro-Sport test the difference between the lowest notch and the highest one, plus the addition of two heavy weights to the piston, increased the average velocity of .22 caliber H&N Baracuda pellets from from 437 to 463 f.p.s. That was a 12 foot-pound kit and the relative energies of those velocities is 8.97 foot-pounds and 10.07 foot-pounds, respectively.

Pro-Sportr spring in bottom notch
The spring end is in the lowest notch with the least preload.

Pro-Sportr spring in top notch
The spring end is in the top notch and the preload is the greatest.

I set this kit up with the spring in the lowest notch to put the least amount of preload on the spring. As I keep saying — I was after smooth shooting and not power. Still, I got power equal to what the rifle had before the tune and it now shoots very smoothly. If the owner desires he can easily remove the spring and adjust the end that’s in the forward guide/tophat to the top notch. I estimate he will gain about 25-30 f.p.s. with the JSB 8.44-grain pellet.

Air Arms Falcon

The next pellet I tested was the 7.33-grain Air Arms Falcon dome. Ten of them averaged 867 f.p.s. The low was 864 and the high was 869 f.p.s. so the difference was 5 f.p.s. That’s a remarkable result from a spring piston rifle that’s just been tuned! At the average velocity this pellet generates 12.24 foot-pounds at the muzzle.

RWS Superdome

Next I tested the 8.3-grain RWS Superdome. Ten of them averaged 789 f.p.s. with a spread of 23 f.p.s, from 779 to 802 f.p.s. That spread is a little large, considering what the other two pellets did, and the energy of 11.48 foot-pounds tells us this is probably not the best pellet for the R10.

Based on the results of these three tests I was prompted to try a heavier pellet. This powerplant seems to like them. The 10.65-grain H&N Baracuda averaged 686 f.p.s. for 10 shots. We know that the magic number is a velocity of 679 f.p.s. — where the velocity in feet per second is equal to the energy in foot-pounds. This pellet is therefore slightly above 10.65 foot-pounds. In fact it registers 11.13 foot-pounds at the muzzle.

Cocking effort

The R10 was supposed to cock with  25 lbs. of effort when new. When I tested the rifle before this tune it cocked with 24 lbs. of effort. After the tune it now cocks with 26 lbs. of effort. Cocking is smooth and I can just barely hear the new cocking plate/shoe as it runs along the slot in the spring tube. It’s an ever-so-slight slight sound and the only one the rifle makes when cocked.


The rifle is tuned. I got exactly what I was after and I think the owner will be pleased when he gets it back. The next step is to test the accuracy. The owner and I talked about that and he said he might buy whatever type of scope I tested it with. Well, my HW-85 has an obsolete UTG 3-12X44 Mini-SWAT scope that I like just fine. While that one of no longer available UTG does have a current version of the same scope, only this one has an illuminated reticle.

Because the HW-85 has the same scope base as the R10, the 30mm BKL high scope rings will fit perfectly. This R10 has a scope stop that the BKL rings don’t need but with it installed the scope will be positioned in almost the identical place on the R10.

The Vortek PG3 HO tuning kit is remarkable. It doesn’t need any extra help from TIAT. It’s dead calm and, except for the issues mentioned during installation, it goes in easily. The R10 is a bit of a chore to tune, but I would imagine that an R9 would be easier. Stay tuned.

SigAir ProForce MCX Virtus AEG airsoft gun: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

Virtus AGE right
SigAir ProForce MCX Virtus AEG right side.

Part 1
Part 2
Part 3
Part 4

This report covers:

  • 110 mainspring
  • BUT
  • Prediction
  • Changing the mainspring
  • Assembly
  • Performance
  • 0.20-gram BBs
  • Rock and roll
  • 0.25-gram BBs
  • Battery
  • Summary

Today we’re going to have a little fun. I know some of you would like to work on spring-piston airguns but you just don’t want to jump into the deep end of the pool — as in buying expensive tools like a mainspring compressor and parts that may or may not work as you expect. Today we are going to change the mainspring in the SigAir ProForce MCX Virtus AEG airsoft gun, and we will do it with two Allen wrenches — nothing more! This is a job any of you can do. Then we’ll test the velocity of the gun and see what impact the new spring has made.

110 mainspring

You may recall that Sig bundles a 110 spring with the Virtus, while the 120 spring comes installed in the gun. First off — what do the numbers 110 and 120 mean? That rating relates to how fast that spring will propel a 0.20-gram BB in meters per second. So a 120 spring should propel a 0.20-gram BB at 120 meters per second, which is 394 f.p.s. That’s regardless of what airsoft gun it’s in.  A 110 spring should propel the same BB at 110 meters per second, which is 361 f.p.s.


Airsoft springs are also rated with an M or an S (which can also be an SP). The M spring is the one that’s rated to toss a 0.20-gram BB as described above. The S or SP spring is rated for a 0.25-gram BB. The velocity in meters per second remains the same, but since the 0.25-gram BB is heavier, the gun will naturally be even faster with a lighter BB. So the higher the number the stronger the spring and M versus S or SP also figures in.

The 110 replacement spring that comes with the Virtus is an M110 spring, and Sig recommends using 0.20-gram BBs in the gun. They don’t say anywhere that I can see whether the 120 spring that comes installed is an M or an S, but given the ammo recommendation, I believe it is also an M120 spring.

So, what sort of velocity did we see from the 0.20-gram BBs with the 120 spring installed? Sig said to expect a 370 f.p.s. velocity, but we saw an average 410 f.p.s. speed. What I just explained was what the manufacturers say to expect from a 120 spring — 394 f.p.s. That’s real close to 410 f.p.s., so again, I think the gun had an M spring. An S120 spring would have given 394 f.p.s. with 0.25-gram BBs and probably 430 f.p.s with 0.20-gram BBs. Of course, that’s just my guess.


So, the Virtus that I’m testing shot on the fast side with its M120 spring — assuming I am correct about it being an M-rated spring. Therefore, I predict that it will also shoot on the fast side with the M110 spring. Instead of 361 f.p.s. I predict a 0.20-gram BB will average 380 f.p.s. I am writing this before shooting the first shot with the new spring.

Changing the mainspring

Changing the mainspring is very easy. First, extend the wire buttstock all the way and then remove the 3mm Allen screw on the right side, where the stock meets the receiver, and the entire stock slips up and off the receiver. By the way, the Virtus manual says the screw is 8mm, but it’s actually 3mm — no doubt a mistake in transcription. When the screw is out, a plastic keeper that it passes through also comes out and the stock slips up and off the rear of the receiver. When reinstalling the stock make sure the V-notches on both sides of the receiver line up with the two heavy wires in the stock.

Virtus AEG stock off
With the screw and keeper out of the stock the entire  assembly slips up and off the receiver.

Once the buttstock assembly is off the gun, the rear of the spring guide is exposed. The manual calls it a screw that you turn 180 degrees, but it’s actually a bayonet keeper. Turning 180 degrees aligns the flanges of the keeper with their raceways and the mainspring pushes the keeper out. Remember that the keeper is under spring pressure, so pressing in on the wrench helps loosen it for turning.

Virtus AEG receiver
With the stock off the rear of the spring guide (arrow) is exposed. Insert a 5mm Allen wrench and turn the guide counter-clockwise 180 degrees.

Virtus AEG  spring out
When the bayonet lugs align, the spring guide is free to come out. This is how far the 120 spring pushes the guide out. You can restrain it easily with your hand.

The two springs compare in this way. The 120 spring is made from heavier wire and the 110 spring is longer — though that may change after a few weeks in the gun. Both springs are wound with what the airsoft industry calls irregular pitch, which means some coils are closer than others. That allows the spring to start compressing easier and then increase in tension the more it’s compressed. It’s supposed to be easier on gearboxes, though you will find a lot of arguments on both side of that issue!

Virtus springs
The softer M110 spring is on top and the 120 is below. It’s not easy to see, but the 120 spring is made from heavier wire. Both springs are wound with an irregular pitch.


The Virtus goes back together the reverse of the way it came apart. And it’s just as easy as it sounds. It’s taken me a long time to describe a process that took me 20 minutes to perform — again with just two Allen wrenches.


Now, let’s find out what installing this lighter spring has done for us.

0.20-gram BBs

First to be tested were 0.20-gram BBs. I believe I am out of the BBs Sig sent with the gun so I used 0.20-gram TSD competition BBs. The average velocity for 10 was 380 f.p.s. Sometimes old BB gets it right on the nose!

The spread went from a low of 370 to a high of 383 f.p.s., so a 13 f.p.s. difference. With the 120 spring the average was 410 f.p.s. with a 6 f.p.s. spread.

Rock and roll

I emptied the magazine on full auto and truthfully could not tell any difference in the cyclic rate this time versus with the 120 spring. There may be some but it’s pretty small.

0.25-gram BBs

Next I tried the same Open Blaster 0.25-gram BBs that I shot before with the heavier spring installed. The average this time was 343 f.p.s. with a 5 f.p.s. spread from 340 to 345 f.p.s. With the 120 spring the average was 365 f.p.s. with a 2 f.p.s. velocity spread. At the end I dumped the magazine on full-auto again, remembering to fire a couple shots on semi-auto afterwards to relax the spring.

I did not load heavier BBs for testing. I think the 0.25-gram BBs are as heavy as I would go with this spring, given the velocity we have seen.

So, the 110 spring varies in velocity slightly more than the 120. Of course this spring is brand new and may settle down a bit after a few thousand rounds have been fired.


I would like to point out that the battery has never been recharged since I started the test and it is still going strong. Not only has it fired many hundreds of rounds including lots of blank shots, it has also been stored charged for two months.


Next we test the gun for accuracy. If the accuracy is reasonably equivalent to the 120 spring I think I will leave the 110 spring installed. It is no doubt a little easier on the gearbox.

This Virtus AEG is a serious airsoft gun, as I have maintained all along. This is the kind of equipment a skirmisher wants to have for close-quarters battle!

Air Venturi Avenger repeating air rifle: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Air Venturi Avenger.

Part 1
Part 2
Part 3

This report covers:

  • Start testing accuracy
  • Bug Buster 3-12X32
  • The test
  • Sight in
  • JSB Exact Jumbo 
  • RWS Superdome
  • Beeman Kodiak
  • Sig Crux Pb
  • Air Arms 16-grain domes
  • Beeman Devastator
  • Sniper Magnum
  • Magazine — the final test
  • Summary

Seldom has a day like this happened in this blog — and I mean that in the best possible way! This is going to be a biggie!

Start testing accuracy

Today we start testing the accuracy of the Air Venturi Avenger that I’m testing. So far the Avenger has stood up very well and I have been hoping that it’s as accurate as everyone seems to say. Well — it is! I have a lot to tell you, so let’s get started.

Bug Buster 3-12X32

I have been thinking about this test for a long time and wondering which scope to mount. The Meopta Optika6 is the best scope I own and would do very well on this rifle, but the Avenger is a lightweight PCP. How about a scope that’s suited to the concept of light weight? I mounted the UTG Bug Buster 3-12X32 on the rifle and it seems ideal to me.

Avenger Bug Buster
BB finds the UTG Bug Buster 3-12X32 scope ideal for his Avenger! It can be mounted far enough to the rear that the eye relief is perfect.

Bug Busters are great scopes but some rifles limit where they can be mounted and that creates an eye-relief problem. Not so the Avenger! Old BB would be proud to have designed this one!

The test

I want to give the Avenger a thorough test for accuracy because it is stacking up to be one of the finest PCPs on the market at any price — and I mean that! So today I am trying to find the one or two really accurate pellets to test at greater distances.

I am testing the rifle at 10 meters and shooting 5-shot groups so I can shoot more pellets. Ten meters is nothing for an accurate air rifle, but you have to start somewhere, and knowing the best pellets will help me in the next tests at greater distances. I shot with the rifle rested on a sandbag and I used the single-shot tray until the end of the test. I did test the magazine, as well, and I will tell you when I did that.

Sight in

I sighted-in at 12 feet, which this lightweight combo makes very possible. I dialed the scope magnification down to 3X and set the parallax as close as it would go. It took me six shots to get on target, and I will say right now that I purposely did not zero the rifle perfectly, in order to preserve my aim point. Once I was sighted in I only adjusted the scope once more. I will add that this scope adjusts on the first shot and seems to have no stiction (when the point of impact changes slowly, over many shots, after a scope adjustment). Let’s go!

JSB Exact Jumbo 

The first pellet tested was the JSB Exact Jumbo. After the first shot I watched the group grow slowly. I knew I had a winner right out of the bag! That’s five shots in 0.136-inches, and folks, that earns the coveted gold dollar — my smallest comparison coin.

An American dime is 17.91mm in diameter. The trime (silver three-cent piece from the mid-1800s) that you will also see today is 14mm in diameter. The type 1 gold dollar (also from the mid-1800s) that I use is 13mm in diameter.

My group comparison standard is to use a dime for groups of 0.20-inches between centers and larger. For 0.15-inches to 0.199-inches I use the trime for comparison, and for groups smaller than 0.15-inches, the gold dollar is used. 

Avenger JSB 5
At 10 meters the Avenger put 5 JSB Exact Jumbo pellets into a group measuring 0.136-inches. Yes, I was shooting too close to say much more, but this is a splendid start!

This group was just a little too far to the left, so I adjusted the scope several clicks to the right. This was the last time I touched the scope!

RWS Superdome

The second pellet I tested was the .22-caliber RWS Superdome. Five of them went into 0.212-inches at 10 meters. With most other air rifles this group would have me jumping up and down, but today I can say it’s okay but not special! Wow!

Avenger Superdome
The Avenger put 5 RWS Superdomes in 0.212-inches at 10 meters. For this rifle, it’s just okay!

Beeman Kodiak

I next shot 5 Beeman Kodiak pellets that are the same as the H&N Baracuda. I wish I could tell you the head size, but Beeman didn’t put that on the tin. I could measure them with a Pelletgage, but that would not necessarily translate to a Baracuda head size that’s printed on the tin. 

This group took my breath away because it is as good as any 10-meter rifle I have tested! Five shots are in 0.082-inches at 10 meters. After the first shot I really could not see the group growing any larger. Robert Beeman used to tell us why .177 caliber was best for target shooting, but aside from the rules that mandate that caliber for matches, it really makes no difference.

Avenger Kodiak
Five Beeman Kodiak pellets went into 0.082-inches at 10 meters. This is the smallest group of the test. As you can see I almost shot my aim point away.

At this point in the test I could see the way things were going. I wasn’t necessarily looking for the most accurate pellets as much as I was looking for the ones that aren’t accurate. That’s a big difference and it only happens infrequently with special air rifles, so I’m enjoying it. It was time to try some pellets I seldom use in tests.

Sig Crux Pb

Next up were five Sig Crux Pb domed pellets. They went into a group that measures 0.314-inches center-to-center. On any other day that would be significant, but not today.

Avenger Crux Pb
Five Sig Crux Pb pellets made this 0.314-inch group at 10 meters.

Air Arms 16-grain domes

The Air Arms 16-grain dome is a premium pellet that I don’t often include in tests because it is so similar to the JSB Exact Jumbo that weighs 15.89-grains. But today I’m glad that I did because 5 pellets went into 0.125-inches at 10 meters. It’s the second-smallest group of the test and deserving of another gold dollar!

Avenger Air Arms
Five 16-grain Air Arms domes went into 0.125-inches at 10 meters. It’s the second-smallest group of the day.

Beeman Devastator

Beeman Devastators are no longer made. They were a hollowpoint pellet with a special head that expanded rapidly. The Avenger put five of them into a group measuring 0.185-inches between centers. It earned the only trime in today’s test.

Avenger Devastator
Five Beeman Devastators made a trimeworthy 0.185-inch group at 10 meters.

Sniper Magnum

Next to be tested were five H&N Sniper Magnum pellets. These odd-looking domes made a 0.228-inch 5-shot group at 10 meters. They also shot away my aim point on the third shot — or at least that’s what it looked like before I saw the enlarged image. It’s possible that this group might have been smaller if I had not had to guess where the center of the bull was on shots four and five. This is a pellet to try again.

Sniper Magnum
Five H&N Sniper Magnums went into 0.228-inches at 10 meters.

Magazine — the final test

Now I tested one of the two magazines supplied with the rifle. They are conventional rotary mags that we see on so many repeating PCPs today. I loaded all 10 JSB Exact Jumbo pellets into the mag, which turned out to be a very good thing when you see what happened. 

The first shot went high and to the left of the center of the bull — very close to where the pellets had gone in the first group, but a little to the right of that one. Okay! Then the next 9 shots went into a group that measures 0.126-inches between centers. This group is high and slightly right of the center of the bull. Those 9 shots would earn the fourth gold dollar if not for that first shot. That shot opens the group to 0.449-inches. What happened? It’s open for discussion. I watched shot two open the group and was heartbroken, except that the next 9 shots all went into the same little hole.

JSB mag 10
Yep — there are 9 pellets in the round hole above the dime. Only shot 1 was to the left. Ten JSB Exact Jumbos in 0.449-inches at 10 meters with 9 in 0.126-inches.


Do I even need to say it? Well, I will. This Avenger I am testing is the most accurate .22 pellet rifle I have tested this year and it’s in contention for the best of all time! And this is a PRICE-POINT-PCP — one that’s sporting a $125 scope! I tell you, guys, airguns like this don’t come along that often.

Yes today was just at 10 meters, and no, that doesn’t really constitute an accuracy test for a PCP like this. But it has my attention. This rifle may not be going back to Pyramyd Air after this test is complete.

The trigger isn’t perfect, but it’s really good. The shot count is off the charts. I’m shooting with the reg. turned all the way down and the hammer spring tension as low as it will go, but in Part 3 we learned that still gives us power in the 22-24 foot-pound region. I will take it!

Will every Avenger in all three calibers be just as good as this one? I don’t know, but I certainly hope so.

Diana Mauser K98 PCP rifle: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Diana Mauser
Diana Mauser K98 PCP.

Part 1

This report covers:

  • Fill
  • JSB Exact Jumbo Heavy
  • Fill to 200 bar
  • Discharge sound
  • Discussion 1
  • Beeman Kodiak
  • Pellet feed with the single-shot tray
  • H&N Hollow Point
  • Discussion 2
  • Trigger pull
  • Summary

Today we test the velocity and power of the Diana K98 PCP rifle. According to the description on the Pyramyd Air web page, this is a 26-foot-pound air rifle in the .22 caliber I am testing. This information helps me select the right pellets to test. A pneumatic in this power range is probably best with medium-weight to heavyweight pellets, though I will also test lightweights, just so we know.


I tried to fill the rifle to 200 bar/2900 psi — the recommended fill pressure, but I waited an instant too long to shut the tank valve and the fill went to 3,000. It’s only 100 psi more.

I will comment now that Diana does not supply a plug to cover the fill port, to prevent dirt from entering and getting in the gun. It won’t affect me because I am testing indoors, but if you want to carry the rifle outdoors, I recommend finding a way to cover that hole. Even a piece of duct tape will work.

The rifle has a magazine that I will also test, but for most of today’s testing I plan to use the single shot tray that comes with the rifle. Let’s get started.

JSB Exact Jumbo Heavy

I got a strange string from the JSB Exact Jumbo Heavy pellet. I will show it to you and then discuss it.

7…………..did not register
8…………..869 onboard pressure gauge read 2800 psi.

Okay, this is a very peaked velocity curve without much of a flat spot. At the highest velocity of 876 f.p.s  on shot 10 this pellet generates 30.9 foot-pounds. That’s well above the 26 foot-pounds it is rated for. With this pellet that energy would be developed at 804 f.p.s. So, if I take that as the standard and accept all 20 shots shown, the rifle got 20 shots that had an 87 f.p.s. spread in velocity.

Fill to 200 bar

I think that spread is too large for shooting anything past about 20 yards. What would happen if I filled the rifle to the recommended 200 bar/2900 psi and shot the same pellet? I was very careful to do that on the next fill. Let’s see what this same JSB Exact Jumbo Heavy pellet does.

10…………848 gauge read 1400 psi

Diana Mauser gauge
After shot 10 the gauge looked like this.

This time I got an 11-shot string that went from a low of 848 f.p.s. to a high of 880 f.p.s. That’s a spread of 32 f.p.s. It’s a lot tighter than 87 f.p.s. At the high velocity the energy generated was 31.18 foot-pounds at the muzzle.

Discharge sound

This Diana Mauser is a suburban backyard air rifle. When it fires it sounds like a mouse cough! The sound is negligible — maybe a 1.9 to 2.0 on the 5-point scale.

Discussion 1

It seems what we have here is a PCP that’s much more powerful than advertised, and also short on breath. It reminds me of the Korean PCPs of the 1990s that got 10 shots and had an equally large spread. Their reservoirs were larger so they put out 65+ foot pounds at their top, but the performance curve is similar. If this isn’t a good example of why a chronograph is an important tool for the airgunner I don’t know what is.

Given the power that’s available I tested a heavier pellet next.

Beeman Kodiak

The .22-caliber Beeman Kodiak pellet is obsolete, but it’s identical to the H&N Baracuda. It weighs 21.14-grains. I carefully filled to 200 bar again and shot the following string.

12…………798 gauge read 1400 psi

At the highest velocity this pellet generated 32.35 foot-pounds. I’m saying there were 12 good shots in this string that ranged from a low of 791 to a high of 833 f.p.s. That’s a spread of 42 f.p.s. At the lowest velocity the energy developed was 29.38 foot-pounds. Because of that, if you stop shooting at 12 shots after a 200-bar fill with this pellet in this rifle, you will be at or above 30 foot-pounds, which is well above the advertised energy.

Eight of the shots in this string (shots 3 through 10) are within 17 f.p.s. of each other. The rifle does seem to like the heavier pellets over the lighter ones.

Pellet feed with the single-shot tray

I noticed that if I held the rifle with the muzzle up while loading, the pellet could slide back on the single-shot tray into the receiver. I took a picture for you, but I don’t think it is a problem. The groove for the pellet continues on back into the receiver and when I pushed the bolt forward the pellet came out of the receiver and loaded correctly every time.

Diana Mauser pellet in receiver
When the muzzle is held up the pellet can slide back on the single-shot tray and disappear into the receiver like this. That’s the nose of a JSB dome. It still seems to feed well.

H&N Hollow Point

I was out of .22 Hobby pellets so I substituted 12.65-grain H&N Hollow Points. They are no longer available but they should give you an idea of what a lighter pellet will do. I filled the rifle to 200 bar. I will tell you right now that this string was a real surprise!

11…………930 gauge read 1400 psi

Wow! I didn’t expect that! An almost straight drop from the first shot to the last. At the highest velocity this 12.65-grain pellet generated 27.59 foot-pounds. At the slowest velocity of 930 f.p.s. it generated 24.30 foot-pounds. This string of 11 shots varied by 61 f.p.s. I think the Mauser PCP doesn’t care for lightweight pellets!

These hollowpoints have a sharp shoulder that caught on the transfer port twice while shooting this string. When that happened I backed off on the bolt and tried again and the pellet went in both times.

Discussion 2

Well, now we know that there are just 10 or 11 shots on a fill — depending on the pellet. We also know that the rifle prefers heavier pellets.

Testing the magazine and shot count

Time to test the function of the magazine. I tested it with the 18.13-grain JSB Exact Jumbo Heavy pellets for which we have a good baseline. And in this string I got another surprise — more shots on the fill. Is the rifle breaking in?

12…………857 gauge read 1400 psi
15…………828 gauge read 1200 psi
17…………did not register
18…………785 gauge read 1100 psi

This string gave 15 shots that stayed within 52 f.p.s. Fourteen of them are within 43 f.p.s. Those 14 shots were between the fill of 2900 psi (200 bar) and the reading that was just above 1200 psi. The rifle may be breaking in and may get even more shots per fill than what we see here after more shooting.

Will it continue to get more shots per fill? I don’t know but it’s very possible. There could be as many as 20 good shots on a fill when the gun is fully broken in. I believe I will return and test the velocity after the accuracy testing is complete.

Trigger pull

The Mauser PCP trigger is 2-stage. Stage 1 is light, at 1 lb. 5 oz. Stage 2 though is heavy and creepy. It breaks at well over 12 lbs. which is the limit of my electronic gauge. It doesn’t feel that heavy but I measured it repeatedly and it pegged the gauge every time. It’s no target trigger for sure but I don’t think it will bother most shooters if they know what to expect going in.


Well, the Diana Mauser PCP is certainly a different air rifle! It has way more power than advertised and is a bit short on the shot count. I will return and test that again after the rifle has a lot more shots on it.

The rifle feeds smoothly from both the magazine and the single shot tray. Domed pellet seem to do the best.

If the Mauser is accurate it will make a good hunting or pest rifle, as well as a good general shooter. Just carry a small air tank to keep it filled.

I plan to shoot targets next. I will use the open sights and shoot from 10 meters. Stay tuned!

Beeman R10: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Beeman R10
Beeman R10.

Part 1

History of airguns

This report covers:

  • Start
  • Scope base off
  • Tip 1
  • Mainspring
  • Remove piston
  • Sleeved piston
  • Threaded spring tube
  • Breech seal
  • Cleaning
  • Piston seal
  • Tuning strategy
  • Trigger
  • Insert the piston with the new Vortek seal — tip 2
  • Last thing — the trigger box!
  • Final assembly
  • Summary

Today I disassemble the Beeman R10 and install the Vortek PG3 tuning kit. I installed one of these in the Air Arms PG3 SHO tuning kit in an Air Arms ProSport last year and the results were very positive. But this R10 is a different rifle in many ways, and I will cover that today as we go.

I am going to show you all the differences and nuances of the R10, but I can’t show everything about disassembly. If you want to see that read the 13-part series titled Spring gun tune. That was about a Beeman R1, but most of the steps are the same for the R10. I will address the ones that aren’t.


The barreled action was out of the stock, so the first step was to remove the Rekord trigger and safety. To remove the trigger, drift out the two pins that hold the trigger unit in the end cap.

Beeman R10 trigger out

When the two pins are tapped out the trigger unit is free to be removed.  Once the trigger is out the safety and spring slide out of the end cap.

When I saw the trigger I thought that this rifle has never been apart, because all the factory grease remains on the trigger parts No tuners I know would leave all that grease on those parts. It serves no purpose.

Before someone asks the obvious question of why Weihrauch puts the grease there if it serves no purpose, let me tell you that you have never seen the assembly of an airgun if a factory. It’s fast! The workers are told to squirt a little grease here and there and they do. Some do more and others less. In some countries where it is very hot perhaps the grease melts and runs over the parts. In others it ends up like this. That’s just the way it is.

Some airguns are dwesigned to need much less grease. The Air Arms TX200 Mark III is an example. So less grease is applied and the lubricity of the parts does the rest.

Scope base off

Next I had to do something that’s unique to the R10. The scope base is attached to the end cap by two screws. But the base is also attached to the spring tube by a flange, so the base must come off before the end cap can be removed. And there was a scope stop attached to this scope base that had to come off first.

Once the two screws are out the scope base should slide forward and come out of the spring tube. It’s held in place by a flange that I will show you. This one was stuck, though, by what turned out to be hardened grease. That’s more of an indication that the gun has never been apart. So I partially unscrewed the end cap with the scope base still on the rifle.

Tip 1

The R10 end cap unscrews from the spring tube. When the gun hasn’t been apart for a long time the cap can be hard to start turning. Once the trigger is out of the gun there is a large slot in the end cap where the handle of a crescent wrench can be inserted and used to start the end cap turning. I use the rounded end of a crescent wrench because it is rounded and will not damage the sharp edges of the trigger slot in the end cap. I also use it to tighten the end cap at the end of assembly. I will also grease the end cap threads so it’s easier to remove next time.

Beeman R10 end cap
I have started to unscrew the end cap. The scope base is still attached to the spring tube, but the end cap screws are out so the cap is free to turn.

You can unscrew the end cap by hand until there are 3-4 threads remaining. Then put it into the mainspring compressor and keep tension on the cap as you slowly unscrew it.

Beeman R10 end cap unscrewed
The end cap is unscrewed all the way, but the mainspring is still pressing against it.

I had no idea of how much pretension the R10 mainspring had, but the compressor was set to allow a long one. Good thing, because it turned out there are three inches of pretension on the spring — one is taken up by the end cap threads and the spring has the other two!

Beeman R10 mainspring relaxed
The mainspring has finally relaxed! As you can see, there is a lot of pretension on this spring!


With the end cap off, the mainspring and spring guide could be removed. This spring is unlike any I have ever seen in a Weihrauch product. What I thought was lube on the spring coils was actually just the shiny metal. There was almost no lube on the mainspring, which is consistent with other Weihrauch airguns I have disassembled.

The spring is canted at both ends — rather visibly at one end. This was the reason why there was some vibration when the rifle fired

Beeman R10 mainspring canted
The mainspring was canted noticeably — especially at the end that went over the spring guide.

Once the mainspring was out I could move the scope base forward until it freed up and slid out of the spring tube. 

Here you see the scope base and the slot in the spring tube where it fits. The square piece on the left underside of the scope base is a flange that slots into the spring tube.

Remove piston

With the mainspring out the cocking shoe is removed from the piston and the piston is slid out of the rifle. There was nearly no lubrication on the piston, either, which leads me to believe that the gun had never been disassembled. If it was, whoever did the work did not lubricate it very well.

Beeman R10 piston
The piston was dry.

Sleeved piston

One R10 quirk is that the piston is sleeved. That reduces the clearance between the piston and the mainspring. The Vortek kit cannot be installed with the sleeve in place, so it has to be removed. There is a small hole at the top of the sleeve to assist you in this task.

Beeman R10 piston sleeve
The piston sleeve has a hole at the top (arrow) to assist in removal.

Beeman R10 piston sleeve 2
This view of the bottom of the piston shows the sleeve better.

Beeman R10 piston sleeve 3
The sleeve is sliding out.

Beeman R10 piston sleeve 4
The sleeve has been removed.

Threaded spring tube

Let me show you the threads in the spring tube. Remember I said that threading the tube was risky? Let’s see why.

Beeman R10 threaded tube
This is the threaded end of the spring tube, where the end cap screws in. There’s not a lot of extra material for leeway.

Breech seal

I was also sent a new breech seal for the rifle. The one that was in the gun looked okay, but when I went to remove it, it broke apart. The Weihrauch seal looks like an o-ring in the gun, but it’s three times as tall and is specially made for their rifles. This replacement seal seemed to be the same tough stuff that the Vortek piston seal is made of.

I’ve never seen a Weihrauch breech seal break apart that way, but I have seen a lot of other airgun seal break apart. So it’s a good thing it was changed. It took me some time to pick out all the broken pieces.

Beeman R10 breech seal
When I tried to pick out the breech seal it crumbled into pieces.


At this point I cleaned the rifle and its parts, plus I looked for any burrs to remove. I found no burrs, and the interior of the spring tube wasn’t that dirty. I use a long dowel with a piece of paper towel wrapped around one end and held on by a rubber band. I usually dip the towel into alcohol, but this time I used acetone, which cleans even faster.

The piston needed to be cleaned inside and out. And I cleaned the head of the piston after removing the old piston seal. The new seal needs to be on a clean piston.

Piston seal

The old piston seal was still in good shape, unlike the breech seal, but since the Vortek kit comes with a new piston seal, I put that one on. It’s made of extremely tough synthetic material which proved a real blessing during assembly.

Tuning strategy

At this point in any tune my experience takes over and I do things my way. When I tuned the Air Arms Pro-Sport I put a thin coating of Tune in a Tube on the mainspring of that PG3 kit, to cut the vibration. The Vortek kit is supposed to dampen all vibration, but I didn’t want to take a chance. But Gene Salvino said in the comments to Part 1 of this report that the Vortek lubricant that is provided is slicker than TIAT, so I decided to give it a try. At worst I would have to open the rifle again to fix my mistake if the kit vibrated.

Here is what Gene said to reader Chris USA,

“DO NOT use TIAT in a Vortek . His [Vortek’s] grease is a synthetic based grease that is very slippery and will not gum up in the cold weather . Zero benefits , the guides shield the noise anyways . TIAT is for high powered guns with factory guides with factory drop in tolerances , the Vorteks are very tight .”

Beeman R10 Vortek kit
The Vortek kit contains a small container of special lube that’s supposed to be much slicker than TIAT.

I lubed the piston seal, the piston body, inside and out, including the central rod that connects to the trigger with the Vortek grease. I lubed the front of the mainspring generously because I couldn’t get the white rear spring guide off the mainspring to lube there. I figured when I cocked the rifle that part of the spring would get some grease.

I didn’t lube the inside of the rifle’s spring tube, which I normally do with moly. The parts that generate friction in the Vortek kit are all held by synthetic parts that have a low coefficient of friction, so I figured Vortek knows what they are doing.


I spent some time cleaning the factory grease out of the trigger. Yes, an ultrasonic cleaner is probably the best way to do that, but I don’t have one. So it’s cotton swabs and paper clips for me.

When I had removed as much grease as possible, I then lubed the sear contact point and the piston rod catch with moly grease.  Before doing that I cocked the trigger by pressing down on the rear if the long piston rod catch until the sear caught. I could then examine the sear contact area with a loupe. You will remember that  I told you in Part 1 that this trigger is adjusted perfectly. I don’t want to do anything to mess it up.

Beeman R10 trigger unit
To check the sear contact, cock the trigger by pressing down on the back of the piston catch lever (arrow shows where it is inside the black trigger box) until the sear catches. The sear contact inspection hole is at the lower left.

Beeman R10 sear
The sear contact is enough to be safe, as this trigger is adjusted. This is about a 10X magnification. The factory grease has not yet been removed. 

Insert the piston with the new Vortek seal — tip 2

I tried and tried for 20 minutes to get the new Vortek piston seal into the spring tube. No matter what I did that seal was not going in past the threads. The seal has a small lip on the back that just will not pass the threads in the spring tube.

Beeman R10 piston seal
That small lip on the rear of the Vortek piston seal would not go past the threads in the spring tube.

Finally, after fiddling with the piston for 20 minutes, I decided to “thread” the piston seal past the threads. In other words, to screw the piston into the spring tube. It worked! This kit also works on a Beeman R9, but because its spring tube isn’t threaded, you will not encounter this same difficulty.

It took me about 5 minutes to thread the seal into the tube, but once past the threads the piston slid into the spring tube the rest of the way. It was by no means easy to move the piston inside the tube, but it did move, once the threads were passed. The seal appeared to suffer no damage from being installed this way. That’s what I meant about its toughness.

Once the piston was inside the tube and connected to the new cocking shoe that I lubricated with the Vortek grease, I was able to slide the entire mainspring with its guides into the spring tube. When it was shoved all the way in only about 3/4-inch of the parts stood out, compared to the two inches with the factory spring.

Beeman R10 spring installed
The Vortek spring and guides go into the piston much farther than the factory parts.

Last thing — the trigger box!

You may not know this and you need to learn. Beeman told the owners of R-series rifles not to over-tighten the rear triggerguard screws on their rifles. This is because Weihrauch used to just punch a hole for that screw into the bottom of the trigger box and then thread the metal flanges that were displaced by the punch. Those threads are extremely tenuous! I want you to see them.

Beeman R10 trigger box
There are the threads that hold the rear triggerguard screw. Don’t over-tighten it! 

At some point after this rifle was made, Weihrauch replaced this method with a small nut that slips into the trigger box, but even that is small and not that strong. Just don’t over-tighten that screw!

Final assembly

The R10 went back together the way it came apart. Again I remind you to read the 13-part Spring gun tune report to see the details.  I have given you all the ones where the R10 differs. Once the barreled action was together and was back in the stock, the rifle was cocked and fired to prove everything worked as it should. It did!

The firing cycle is now completely dead and free from vibration. This is as good a tune as I could ever hope for. This Vortek kit works exactly as described and does a remarkable job. It’s a $400 tune for $90, if you do the work. I will say that a mainspring compressor is needed because those fine threads on the end cap are hard to get started.


I can do a job like this on an R1 in about 45 minutes. This R10 took 3.5 hours to do the same things. Part of that was because the rifle may never have been apart and part of it was the special design of the R10. The Vortek piston seal made installation of the piston take longer, but if you screw the piston in like I mentioned you’ll avoid the time it took me.

So — what did the Vortek kit do for this R10? To find that out you’ll have to read the next part of the story.