FX Radar Pocket Wireless Chronograph: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

FX chronograph
The FX Radar Pocket Wireless chronograph.

This report covers:

  • No manual
  • BB freebie
  • The app is the manual — sort of
  • Setup 
  • Batteries
  • Easy!
  • Mounting
  • The test
  • Wake up, BB!
  • Woopie!
  • Last shot
  • Email the data
  • I like this chrono!
  • Summary

Today we look at a chronograph that uses all the latest technology to deliver its results to wherever you want them. It’s the FX Radar Pocket Wireless Chronograph. I’ll tell you right now — this one is a hands-down, gold-plated winner!

No manual

We learned when we looked at the FX Dreamlite rifle that FX doesn’t do paper manuals very well. But not with this chronograph, because it has no paper manual at all. I went online to the Pyramyd Air manuals (in the resources section) thinking the manual had just been left out of the box. No — there is no manual — as in none, nada, kein, ingen!

What you are supposed to do is get the app for your smart phone, because this chronograph works with a smart phone. Or you can go to the FX website and look at their tutorials for setting up the chronograph. I did that and when the video stopped all the up-front music and silliness and got down to business I saw I needed the chrono app. So I stopped the video and got the app.

BB freebie

FX — here is a freebie from BB. Make it clearer on your box that step one is to get the app. You wrote it on the box and then covered most of that up with your UPC sticker. Think!

The app is the manual — sort of

When I downloaded the app and set it up on my phone, there were instructions about what to do next. The trouble is, when you page through the screens you loose the information you just saw. A small sheet of paper instructions inside the box would have been so helpful!

Why am I belaboring this point? Because half the buyers of this product are old silverbacks like me who don’t play with their smartphones all day. We use them for telephone calls. Did you know they can also do that? It’s not that 36-year-olds don’t like airguns. They do. But 36-year-olds probably have families to support, while us old guys are finding more disposable cash, now that the kids have flown the nest.


Once the app was installed (it took only a minute) I followed the online directions and was set up in less than three minutes. So, the total time it took to get this chronograph up and running breaks down like this:

BB looking for the manual in the box and on the box — 10 minutes
BB going to the Pyramyd Air manuals page looking for the manual — 10 minutes
BB going to the FX website and watching the chronograph setup video — 5 minutes
BB actually setting up the chronograph, once the directions were found — 3 minutes

That’s a total of 28 minutes, of which 25 minutes were wasted.


This chronograph needs three AAA batteries. They fit inside a battery compartment that’s held shut by a single screw. Replacing that screw was the hardest thing I did during the setup.

FX chronograph batteries
Three AAA batteries power the unit.


Once you are into the app everything becomes easy. In fact, I was in the app, had the chrono booted up and ready to go so quickly that I had to scramble to find an airgun to test. I wanted one that I had tested before and one that I knew was relatively stable, so I selected my Air Arms S510XS Ultimate Sporter. Now, before you tell me how I should test this device — I know you want me to test it alongside a second chronograph. That comes later. Today I’m just discovering how this thing works.


It should be pretty obvious in the first picture how this chronograph is mounted. It clamps directly on your gun’s barrel. What about pistols? We’ll explore that later.

Use two stout rubber bands to wrap around the barrel and slip the ends over pegs on the chronograph feet. Rifles like the AirForce TalonSS are naturals for mounting. Rifles with slimmer barrels like the S510XS I’m using today may require a second wrap of the rubber bands.

FX chronograph mounted
The chronograph is mounted to the barrel of the Air Arms S510XS. As you see, it took two wraps for each rubber band.

The test

I went to Part 2 of the S510 test that I did back in September of 2019 and I picked the RWS Superdome pellet, because I used it in that test in several ways. The rifle was still filled (from 18 months ago) and set to high power. I aimed at the pellet trap, making sure to align with the skyscreens of my Shooting Chrony and I fired. A nice lady’s voice on my Smart Phone told me that the shot had gone out at 960 f.p.s. I wrote that down on a piece of paper like I always do and then I looked over at my phone. Wow!

FX first look
Wow! This is stuff I normally write down — and a whole lot more!

Wake up, BB!

Then it dawned on me. Why was I writing down the velocity when I had this thing running? This was going to keep track of everything for me! Hot dog!

And why was I taking extra care to align the rifle barrel with the skyscreens on my Shooting Chrony that’s set up on my table? It wasn’t turned on and they weren’t even working! This radar chronograph was doing everything.


I continued shooting and the nice lady kept telling me what each pellet had done. Then it occurred to me that if my smart phone was recording each shot, perhaps it was also making a list, just like the ones I always used to make on paper. Sure enough, it was!

Last shot

However, on the 9th shot the nice lady said nothing. And the display on my phone didn’t change. Oh — I’ve seen this before. The chronograph didn’t record that shot! Sure enough when the 10th pellet went out the spout the chrono thought it was shot number nine and recorded it that way.

FX chronograph last shot
This was the last shot in the string. The chronograph failed to record the 9th shot, so this became the 9th shot. Pardon the flash in the lower right corner of the phone screen, but I was too lazy to get out the tripod. And I forgot I could take screen shots on my phone. See how difficult it is to grow old? Ain’t no graceful about it

After the last shot I looked at the icons at the bottom of the screen. What would I like to see? I’d like to see the first string, because at this point, that’s what I’m interested in. So I touched the Shot String icon with my finger and the string came up.

FX chronograph first string
The first string, where the chronograph failed to record one shot.

What did I want to do next? Why — email the shot string to my computer so I could use it in this blog. I didn’t know which icon to press and as I was looking at all of them a page came up where I could edit the data about the pellet that was used. I tried to enter the data and the software “corrected” me from saying RWS Superdomes to res (whatever that means) superfine. So whatever software is used for this screen, it isn’t optimized for the chronograph. The way it works I’m guessing Siri is behind the screen making corrections to what the committee of millenials at Apple knows I really meant to write. The good news is that the software allows you to blunder on if you make corrections to their “corrected” entry. Goodie!

FX chronograph correction
This is me struggling to correct the data I enter into one of the screens.

Remember — this is what happens when THERE IS NO PAPER MANUAL!!! 

Email the data

I then emailed the data to my computer and here are the results. The average for this 9-shot string of Superdomes today was 948 f.p.s. The high was 960 and the low was 942. That’s a spread of 18 f.p.s. 

When I tested the same rifle and pellet at the same power level in September 2019 the average was 941 f.p.s. and the spread went from a high of 958 down to 933 — a 25 f.p.s. difference. Based on just that we see that the two chronographs agree closely. But I will still test them together in the future.

I like this chrono!

I’m buying this chronograph from Pyramyd Air. I’m doing it because first, Shooting Chrony no longer seems to be in business and I do need a good backup chrono. And second because this FX Radar Pocket Wireless Chronograph frees me from a lot of duties!

Now, some of you don’t own a chronograph yet and you want to know whether this one can be used in all situations. I don’t know the answer to that, but it’s one of the things I plan on looking into.


The FX Radar Pocket Wireless Chronograph is a very useful tool. The documentation suffers a little, but once you overcome that, the device works well. There is a lot more testing to come before I can pronounce final judgement, but this is one piece of kit I am rooting for!

Diana 27S: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Diana 27S
Diana 27S.

Part 1
Part 2

A history of airguns

This report covers:

  • SHOT Show
  • Odd-sized breech seal
  • Grainger
  • Velocity with Air Arms Falcon pellets
  • Fooled around
  • WHAT!!!?
  • On with the test — JSB Exact Heavy
  • Chronograph error
  • Cocking
  • 27S
  • Cocking behavior
  • Firing behavior
  • RWS Hobby
  • Summary


I’m at the SHOT Show today. Today is Media Day At The Range, so I’m looking at all the new airguns that are on the range in Boulder City. Yesterday I went to Sig Range Day, so tomorrow I will have a report on both events. The show opens on Tuesday, so the Wednesday blog will be my first report from there.

Today we look at the velocity of the Diana 27S we are testing. If you recall, in Part 2 the breech seal failed and I couldn’t test the rifle. I replaced the seal with a temporary leather one and the velocity jumped from the mid-300s to the high 600s. I said then that it was the largest velocity increase I have ever seen from just replacing a breech seal. I expected a gain of 60-80 f.p.s. Several readers made similar comments.

Odd-sized breech seal

When I measured the old seal I expected to find numbers that were even, numbers that made sense! Instead I found the old seal’s material diameter (the thickness of the ring) was 2.4mm. The inside diameter was 8.3mm and the outside diameter was 13.1mm. Okay, where is the camera — I’m on Candid Camera, right? I expected a ring with a thickness of 2.5mm, an ID of 8.5mm and an OD of 13mm. Who would make something common like an o-ring with such random and odd dimensions? The ring wasn’t designed for Diana. Diana selected the ring from what was available and designed their airguns to fit.

Apparently, though, someone did design a ring like this because when I went to Grainger looking for one, there it was — 2.4mm by 8.3mm by 13.1mm! The reason I was so skeptical is because when it comes to measuring things I’m a cut-three-times-measure-once-and-then-hire-somebody-else-to-do-the-job kinda guy. But, listening to all of you guys with skills, I figured I could at least give it a go — might provide some fodder for a funny blog!


So I placed an order with Grainger for 25 o-rings. I have about 6-8 Dianas that need these seals, and the way I love these guns more can come at any time. The rings arrived last week, and, with considerable trepidation, I installed one in the 27S. Then I set up the chronograph and fired the first tentative shot.

Diana 27S breech seal
The new o-ring/breech seal from Gainger fit perfectly.

Velocity with Air Arms Falcon pellets

Okay guys, we will start the velocity test with the Air Arms Falcon dome pellet. Ten Falcons averaged 689 f.p.s., for an average muzzle energy of 7.73 foot-pounds. Remember — the magic number of 671 f.p.s. is the velocity at which the energy of the pellet in foot-pounds is equal to the pellet’s weight in grains.

The spread ranged from a low of 672 to a high of 710 f.p.s. That’s 38 f.p.s., which is high.

Fooled around

After that I shot some more Falcons and got a string of three that measured 320, 309 and 310 f.p.s. — WHAT!!!?


Right after installing the new breech seal and shooting the gun at velocities in the 690s, I suddenly got one at 374 f.p.s. And that is when it hit me. The new breech seal DOES NOT add 300 f.p.s. to the velocity of the rifle! I had shot through the chronograph in such a way that the first skyscreen was triggered at the wrong time. I know that because I can now do it anytime I want.

It isn’t common but I have seen this phenomenon before. If the muzzle of the gun is too close to the first skyscreen (with Shooting Chrony chronographs) you will get a reading like this. In the case of this Diana 27S I also have to point the barrel slightly downward by a few inches at 3 feet to make it happen every time. That is what happened in the last test, but I didn’t catch it until today. It was just the way I was sitting that made it happen. Apparently the Diana 27S is just long enough to put the muzzle in the exact right spot for this to happen.

So — chronograph users beware. And everybody — a new breech seal should not increase velocity by 300 f.p.s. unless there was no seal to begin with!

On with the test — JSB Exact Heavy

Next up is the JSB Exact Heavy pellet. At 10.34-grains this dome is on the heavy side for a rifle of this power but I have seen excellent results from such pellets in weaker airguns in the past. Ten JSB Heavys averaged 555 f.p.s. from the 27S. The spread went from 552 to 560 f.p.s., so a difference of just 8 f.p.s. At the average velocity this pellet generates 7.07 foot-pounds at the muzzle.

Chronograph error

I got two “Error 2” messages on this string. That message means that skyscreen 2 isn’t seeing the pellet. This is something I am familiar with. Unless the pellet missed passing over the skyscreen it means something has fallen onto the widow above the screen’s sensor. As close as I shoot I knew I wasn’t missing the screen, so it had to be an obstruction. When I looked I saw exactly what it was and was able to clean the screen and get going again.

Diana 27S skyscreen
I shoot with the chrono so close to the pellet trap that stuff sometimes falls on skyscreen 2. There is a smashed lead pellet on the left and a large piece of paper on the right. Remove all the stuff and wipe the screen window with a cotton swab and you’re back in business!


I reported in Part 2 that the 27S cocks with 24 lbs. of effort. That’s more than I expect from a Diana 27, but this isn’t a 27 — it’s a 27S.


The Brits call the 27S the 27 Super, and apparently it was sold to them under that name. They also know of a 35 Super model that I never heard of. Well, looking at both the cocking effort and just the velocities we have seen thus far I think the 27S is more like the Diana 35 than it is like the Diana 27. In fact, the Diana 35 that I tested and tuned last year shoots at lower velocities than this one.

Cocking behavior

The 27S cocks with a slight scraping noise that is common to rifles that have two-piece articulated cocking links. The solution is lubrication, which I will apply when I go inside.

Firing behavior

This rifle shoots with a jolt and a lot of buzz that isn’t common for the other vintage Dianas I have experienced. I will have a look around inside for what can be done and also to see what that anti-beartrap mechanism looks like. But while I’m inside I will lube the rifle with Tune in a Tube in both the mainspring and ball bearing trigger areas. In fact, I am curious to see whether the ball bearing trigger in the 27S looks like the one in a 27 or the one in the 35 that has a few additional parts.

RWS Hobby

This is the last pellet to be tested. RWS Hobby was the speed demon of its day, which was contemporary with the vintage Diana line we have examined. I have found in recent tests that Falcon pellets, though slightly heavier, are often faster, but we shall see.

Ten Hobbys averaged 660 f.p.s., so true to form they are a little slower than Falcons. However, the Diana 35 that I tuned last year averaged 601 f.p.s. with a 26 f.p.s. velocity spread with Hobbys. Today the 27S low was 650 and the high was 671 f.p.s., so the spread was 31 f.p.s. At the average velocity the Hobby generates 6.77 foot pounds.


That’s it for this report. The new breech seal tells us what we need to know about this rifle — it’s in good condition and probably shooting like it did when new.

I would also like to add that today was a big learning day. We learned or were reminded about some quirks of chronographs that I hope will help some of you.

The next report will be a disassembly and examination of the insides of the 27S. And, if it cooperates, I will give it a lube tune and button it back up for another velocity and firing behavior report to follow. So, stay tuned!

Air Arms Pro-Sport: Part 7

by Tom Gaylord
Writing as B.B. Pelletier

Air Arms Pro-Sport.

Part 1
Part 2
Part 3
Part 4
Part 5
Part 6

This report covers:

  • Disassembly
  • Rotate forward spring guide
  • The washers
  • Factory top hat
  • Last note
  • Assembly
  • Relubed
  • Gun back together
  • Velocity with RWS Hobbys
  • Velocity with Baracuda 5.50mm heads
  • Cocking effort
  • The question
  • Summary

Today we look at the Air Arms Pro-Sport with the Vortek PG3 tune kit installed at its most powerful setting. This test was suggested by reader Yogi in the comments to Part 5.

“To finish up the review, how about exploring the other 2 notches in the PG3 kit? Maybe one notch is full OEM power, second notch is the desired 12 foot-pounds, and the third one(the one you have it set on) is good for 10.5 foot-pounds.

This way you have a full report on the Pro-Sport AND the PG3 kit.”

I though that was a great idea. Unless I test it, who knows what the other notches will do? And also there are the two heavy washers that add weight to the piston and more tension to the mainspring.

What I won’t do is test every possible combination of the kit. Besides the three notches there are two washers, so that’s a possible 9 different combinations to test — low notch no washers, low notch one washer, low notch 2 washers, mid notch no washers etc.

Instead, I will go to the opposite end of possibilities and set the mainspring on the high notch with two washers installed. That will bracket the power possibilities.


The Pro-Sport came apart in a few minutes with no mainspring compressor needed. Remember that with this Vortek kit the pretension on the mainspring is even less than on the factory gun and even that doesn’t need a compressor.

Pro-Sport Vortek kit
The thousand-word picture. The mainspring is in the lowest notch from the previous tune. The two washers from the Vortek kit are going in ahead of the forward spring guide (black thing the mainspring is wound around) that’s inside the piston. The factory top hat is shown below. One of the washers is stuck to the tip of a magnet to show that it’s ferrous.

Rotate forward spring guide

To get the end of the mainspring into the highest notch in the base of the forward spring guide, the spring guide has to be rotated. However, the inside diameter of the relaxed spring is smaller than the outside diameter of the spring guide — so the spring is on the guide extremely tight. It look me 20 minutes of fiddling with a screwdriver to move the guide high enough to make the slight rotation that was needed. You don’t want to grab the base of the guide with pliers because it is synthetic!

After that was accomplished the rest of the job took mere minutes. But before I go there, let’s look at what I’m about to do.

The last tune was with the spring set in the lowest notch of the spring guide. And no washers were used. So the piston was almost as light as it could be. By removing the synthetic spring guide it would have been a few grains lighter, but the spring would then have had room to vibrate on the piston stem. Vibration is a bad thing, so those few grains of weight are well spent.

The washers

I weighed the two washers, which are steel. One weighed 85.5 grains and the other weighs 86.2 grains. When I add that the two should weigh 171.7, but for some reason my scale says 171.4 grains. We are talking about a weight difference of a postage stamp, so it may be more in the technique I was using to place them on the scale than any real weight difference. At any rate, an additional 171.4-grains of weight is being added to the Pro-Sport piston.

Pro-Sport Vortek washers
Both Vortek washers together weigh 171.4 grains. They will be going into the piston ahead of the mainspring.

Factory top hat

For curiosity I also weighed the factory top hat that goes into the piston like the washers. It weighs 352.2 grains, or 180.8 grains more than the two washers. It’s a little over twice the weight of the two washers. That’s interesting but I don’t know why.

Pro-Sport top hat
The factory steel top hat weighs 352.2 grains.

Last note

If someone reads this entire report they will discover that I removed the sliding compression chamber for the first tune in Part 5. I did it because the piston didn’t want to go into the chamber when I started assembling the gun. But it really isn’t necessary to do that. Just fiddle with the piston and the piston seal will eventually clear and go in the chamber. This time I did not remove the sliding chamber and the time to assemble was cut by several minutes.


I won’t show you the entire assembly of the rifle because that was covered pretty well in Part 5. I will just show you the order of the parts as they go back into the gun. The two washers go onto the piston rod first. They add that 171-grains of additional weight to the piston, which should change its performance with heavier pellets a little. They also add perhaps a quarter-inch or a little more of preload to the mainspring.

The higher notch on the spring guide also adds a little preload to the spring. I would guess that together the notches and the two washers add about 3/8-inch of preload. That isn’t much, so Yogi, I doubt we are going to see the factory spec with this kit. I think it may get a little closer to 12 foot-pounds, which is what the specs tell us to expect.

Pro-Sport notch
There is the end of the spring in the highest notch. It isn’t seated all the way but when I cock the rifle it will seat.

Pro-Sport assembly
And here is how the parts go back in the piston and then into the rifle.


Handling the parts during this procedure removed most of the Tune in a Tube that was on the outside of the mainspring, so I added just a bit as the spring went back into the gun. It was still coating the inside of the spring, the rear spring guide and the sliding chamber so I left those alone.

Gun back together

Excluding the 20 minutes I spent playing with the forward spring guide, the job took 30 minutes including pictures. That’s from shooting condition back to shooting condition. It was now time to test the results!

Velocity with RWS Hobbys

In the previous lightest possible tune the kit pushed 11.9-grain RWS Hobby pellets out at an average 633 f.p.s. for 10.59 foot-pounds at the muzzle. With the PG3 tune set to maximum the rifle now launches Hobbys at an average 667 f.p.s. for an energy of 11.76 foot-pounds. The lightest tune gave a velocity variation of 11 f.p.s. This tune gave a range of 16 f.p.s. — from 660 to 676 f.p.s.

Velocity with Baracuda 5.50mm heads

In the previous lightest possible tune the kit pushed H&N Baracuda pellets with 5.50mm heads out at an average 437 f.p.s. for 8.97 foot-pounds at the muzzle. But remember, we added 171.4-grains of weight to the piston besides increasing the mainspring preload. This time Baracudas average 463 f.p.s. for an average 10.07 foot-pounds at the end of the barrel. The spread previously was 10 f.p.s. and this time it’s 14 f.p.s. — 456 to 470 f.p.s.

Cocking effort

The cocking effort felt almost the same with possibly one or two more pounds of effort needed to cock the rifle. On my scale it measured 37 pounds of force required, where with the lightest tune it was 35 lbs. and from the factory 48 lbs.

Firing behavior

I can’t detect any difference in the firing behavior from the previous tune. Recoil seems the same, too.

The question

Should I test the rifle for accuracy again with this tune? It’s bound to be very close to where it was before.

And how should I send the rifle back to Pyramyd Air — with the tune just installed or returned to factory spec? I guess I’m asking whether you think anyone would want to purchase a .22-caliber Pro-Sport that has been tuned to 12 foot-pounds?


I don’t know if this is the last report or not. I’ll await your decision on that.

I have to say I am thoroughly impressed by the Vortek PG3 tune kit that delivered EXACTLY what was promised! With all the variables involved (TIAT and me being two of them) I think it’s remarkable it turned out as well as it did.

Diana 27S: Part 2

by Tom Gaylord
Writing as B.B. Pelletier

Diana 27S
Diana 27S.

Part 1

A history of airguns

This report covers:

  • Velocity day
  • A happy accident
  • Breech seal
  • No problemo!
  • BB isn’t daunted
  • Problemo
  • BB has a backup
  • What size are the seals?
  • What now?
  • Cocking effort
  • Trigger pull
  • Today’s report
  • Summary

Today is Part 2 of my test of the vintage Diana 27S. From the comments to Part 1 we learned that several of you own them, but you all seem to live in Europe and the UK. This model is very rare in the U.S. Today’s report is about a failure that turned out to be a huge success!

“Oh, oh! BB’s talking like Mr. Miyagi again! Better get out the rags and car wax!”

Velocity day

I normally test velocity on Day 2 and that is exactly what I intended to do. My guess was that a .177-caliber Diana 27 should shoot around 650 f.p.s. with lighter pellets when it’s in good condition. I put five drops of Crosman Pellgunoil down the air transfer port that is located behind the barrel when it’s closed and then I shot three shots to just spread the oil around. Normally I would cock and uncock the rifle to spread the oil, but we learned in Part 1 that the 27S has an anti-beartrap device that prevents uncocking except by firing.

A happy accident

The oil proved to be a happy accident because of what happened next. The first recorded shot with an Air Arms Falcon dome went out the muzzle at 542 f.p.s. That’s a little slow but I can work with it. However, the next 5 shots went like this.


Wow! This rifle is way off where I expected it to be. But remember that happy accident I mentioned with the oil? It came out as a mist on the first shot, which was a diesel. I saw oil mist shoot out the muzzle and also around the breech. Ah HA! The breech seal is weak.

Breech seal

And here is the first bit of knowledge. The breech seal did not appear to be bad. It was just a little flat, but well within tolerances for a normal o-ring seal. But when I removed it I discovered it was as hard as a rock! It was flat but also immovable — allowing compressed air to rush around it. An o-ring in the breech should push forward when compressed air gets underneath it and lifts it to seal against the breech tightly. This one wasn’t moving. As long as the breech was dry I couldn’t see the air squirting out, but that oil mist made it instantly visible.

No problemo!

Well I am the great B.B. Pelletier, and a couple months ago I ordered a huge assortment of o-rings in both SAE and metric sizes. I’ll get this little puppy back on track in no time.

Knowing that the German manufacturers had used metric o-rings, I looked through my huge assortment — only to discover that I didn’t have the size metric ring I needed. Knowledge number two is — a huge assortment of o-rings doesn’t contain rings of all sizes. Fate conspires to ensure that the size you need is not in the box! That’s the same Fate that hides one of each pair of your sox in the dryer.

BB isn’t daunted

But Fate was dealing with BB Pelletier this time and I had a second huge box of SAE o-rings, as well. I would find one that’s the perfect size and laugh at Fate who thought that, just because it isn’t labeled as metric, I wouldn’t know I had one that fit!


Nope. Fate was laughing at me. If the o-ring was the right diameter it was made from material whose cross-section is too thin to do the job. If it was the right cross-section, it was not the right size. Ha, ha!

BB has a backup

What Fate didn’t know was B.B. has a stash of odd-sized o-rings that he has collected over the years. I brought them out and, wouldn’t you know it, those that were thick enough were the wrong size and those that were the right size were too thin.


Then Fate’s prettier sister, Luck, stepped in. Because, among my collection of odd-sized o-rings, was one leather breech seal I had made years ago — probably for another Diana rifle. It wasn’t as thick as it needs to be and also was not as well-formed as I would like which is why I never used it, but it was the right diameter. So I installed it and tested the rifle again — still shooting the Falcon pellet. Here is what I got.


Wow! A three-hundred f.p.s. boost — just from having a tight breech seal! But what about the last two shots? I think the leather, which was the right diameter but not the right thickness, got pushed back and flattened out too much, then started leaking air again. I could shim it up and get it to work, but I was after something more refined.

Diana 27S breech seal
The leather seal I installed is too thin for the breech and has already flattened out after three shots. But it told me what I needed to know!

What size are the seals?

Okay, here comes knowledge number three. What size is this o-ring? When I measured it the first time in the gun, the numbers didn’t make any sense. I got a material thickness of 2.4mm with an outside diameter of 13.1mm and an inside diameter of 8.3mm. What a whacky set of numbers! Surely such o-rings don’t exist and I’m just not measuring them correctly?

Then I went to Grainger’s website. Such o-rings DO exist with those exact dimensions! Golly — this stuff really does work!

What now?

Okay, what do I do now? I could order a Diana 27 breech seal from Chambers Gunmakers, but they are currently out of stock. Even if they had one I would end up paying about seven to ten dollars for just one seal and have to wait about two weeks for it to arrive. Instead I decided to spend more money and save more by ordering the o-ring in bulk from Grainger — the same guys I bought the o-ring sets from. Each one will cost me about $1.15 this way and I should have them on Monday. Sure, I will have many more seals than I need, but Diana uses the same size seal for many of their spring-piston rifles, so what I am really doing is stocking up.

Cocking effort

I have to say this 27S cocks harder than I expected. The Diana 35 I tuned with Tune in a Tube cocked with 16 lbs. of effort. That is off-the-charts good for a Diana 35 and much lighter than this 27S. Of course the 35 barrel does measure 19 inches while the one on the 27S is about an inch shorter.

I guessed the rifle cocked with 24 lbs. of effort. The scale agreed with me when I tested it, which sounds like I tested first and then wrote about it, but I didn’t. You have to remember I have done this same test hundreds of times before, so I’m getting pretty good at guessing the effort.

Trigger pull

The two-stage trigger breaks at 1 lb. 8 oz. It’s light enough but not entirely crisp. I’m hoping some lube will sort that out.

Today’s report

This was a report that was supposed to go one way and instead went another. I learned a lot from it. Here is what I learned.

A breech seal can look okay and still be leaking air.
O-ring sets don’t contain every size of ring.
A good breech seal can add hundreds of f.p.s. to the velocity.
O-rings don’t always conform to even dimensions.


I know you machinists are laughing up your sleeves at how dumb I am, but if I don’t admit this stuff publicly there are guys who need to know it that will never find out. And, even if I am naive on the subject of o-ring sizes, who knew the right ones could boost the velocity of a low-powered airgun like a Diana 27S by over 300 f.p.s.? I sure didn’t. In the past I have seen gains of 60 and 80 f.p.s. when breech seals were changed, but today was a real eye-opener.

Will this rifle deliver the same 680 f.p.s. with Falcons when a fresh o-ring is installed? I don’t really know. I expected it to shoot around 650 f.p.s. and would be very satisfied if it ended up there. If it does the rifle is shooting where it should and all I have to do is go inside and lubricate it a little. This is going to be a good series!

What does the new year hold?

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • What the new year holds
  • Big bores
  • High-tech projectiles
  • Price point PCPs (PPP)
  • Basic features of a PPP
  • Things that are good to have
  • Kiss of death for a PPP
  • Horsepower wars over?
  • Optics
  • Electronics in scopes
  • Scope mounts
  • Air compressors
  • Replica airguns
  • A dual-power spring-piston breakbarrel
  • M16 replica
  • M1 Garand replica
  • Summary

Happy New Year! May 2020 be a year of vision for all of you!

What the new year holds

I know a lot of you are trying to peek behind the curtain, to see what’s coming down the line. Some writers will divulge things, but I won’t. I would rather wait and see how something is presented before I announce it to the world.

But that doesn’t mean I don’t know some of the things that are coming. Today I would like to share a glimpse into the coming year with some things I know and also the trends I see unfolding. Let’s go!

Big bores

The coming year will be a hot one for big bore airguns. Expect to see muzzle energy over 800 foot-pounds, and this year it will be in actual production guns — not those that have been held up for scrutiny but have never quite made it to production.

Look for the outsider manufacturers — the ones not known for making big bores — to either increase their presence in the big bore arena or to enter it for the first time.

High-tech projectiles

Along with the big bore guns, I see an increase in projectiles that are designed to give greater performance. There is a lot of room for innovation here and the smaller big bore calibers (.257-.357) are where the largest potential benefits lie.

Look at self defense pistol calibers. Years ago the .45 caliber was highly touted, but when specialized .40-caliber and 9mm defense projectiles began hitting the market, calibers as small as .380 rose to credibility. The same could happen in the airgun world. Certainly the smaller projectiles travel much faster and speed is often a critical component of performance with high-tech projectiles.

Price point PCPs (PPP)

The price-point PCP (precharged pneumatic) took the world by storm a few years ago and quickly became the hottest sector of the smallbore market. Look for more new models, plus gen II and perhaps even gen IIIs that correct errors made at the initial launch.

Basic features of a PPP

Shrouded barrel
Good trigger
At or under $300
Foster fill coupling (at some place in the fill line)
Light weight

Things that are good to have

Regulator (user adjustable from the outside of the gun)
Fill to 2,000, or to somewhere below 3,000 psi
Better adjustable trigger (Marauder grade)
Adjustable power
Reasonable power and number of shots
.177 — 18 foot-pounds and 20 shots
.22 — 22 foot-pounds and 20 shots
.25 — 25 foot-pounds and 18-20 shots

Kiss of death for a PPP

Fill higher than 3,000 psi
Proprietary fill coupling
Too much weight

Horsepower wars over?

Yes and no. For spring-piston airguns the horsepower wars are pretty much a thing of the past. Oh, there will still be some rattletrap breakbarrels at the discount stores, because their buyers haven’t watched the market as closely as mainstream airgun retailers, but the days of the “1,600 f.p.s. breakbarrel” have come to an end. But the horsepower wars are not over. They have just shifted to PCPs and especially to big bores.

Today’s airgunners seem enraptured with 80 foot-pound .25-caliber smallbores and 700 foot-pound big bores. Where does it end? Well, here is a little secret. A 100-pound anvil traveling 100 f.p.s. generates 15,547 foot pounds of energy. The secret to muzzle energy in airguns (because velocity is restricted by physics) is the weight of the projectile. But a heavy projectile may not be accurate or even stable in a given airgun. In other words, the heaviest projectile may just be for bragging rights.

Nevertheless, high numbers sell airguns. And muzzle energy is what many buyers are focused on today. So expect airguns with more muzzle energy this year.


I do know some specific new scopes that we will see this year. I’m sworn to secrecy but there are some things coming that you readers have specifically asked for.

Airgun scopes have lead the field of optics for years. The side focus parallax adjustment was on airgun scopes two decades ago, and firearms scopes only got it 5-7 years ago. Scopes with internal bubble levels are still not in the mainstream for firearms, yet they are so necessary for long-range accuracy.

Electronics in scopes

Look for more affordable thermal imaging devices and videocamera recorders in scopes of the future. And look for the prices to fall as they proliferate.

Scope mounts

Adjustable scope mounts that compensate for barrel droop are another airgun innovation. Though the AR-15-class rifles are notorious droopers, many of their users are not aware of this and adjust the droop out with elevation adjustment, alone. Then they wonder why they can’t hold a zero, when we airgunners have known why for decades.

Air compressors

Look for prices to drop this year as companies rebrand the Chinese compressors with upgraded parts and design. And, with the price drop, look for more people to enter the world of precharged airguns.

Also, look for more small compressors that are made to top off guns and not tanks. In the past these had to be connected to shop compressors, but now they stand alone and fill to 4,500 psi readily.

Spring rifle repeaters

Repeating spring-piston air rifle are another hot topic of the past few years. Look for more of them to surface this year and look for the focus to be on a lower profile, now that Gamo has set the bar with the Swarm Fusion 10X.

Replica airguns

This market has always been hot and could be called a perennial favorite. Do it right and succeed in a big way. But there are two parts to success. First the gun you copy has to already be well known. And second, your copy has to be perfect.

The M1 Carbine is a favorite of service members and shooters, in general. It’s small, light and handy to carry and use. And its replica airgun copies start with the Crosman BB gun of 1966 and are still going today with the Springfield Armory M1 Carbine. I look for a pellet-firing version of the carbine soon and eventually a precharged version.

The M14 was a not-so-popular transition that followed the Garand in the 1950s and ’60s. Service members who used it liked it, but the government wanted to move to a smaller cartridge in a lighter platform so the M16 replaced it. Look for an accurate replica of the M14, as the M1A (the civilian semiautomatic version) that first shoots BBs and eventually pellets.

Places where the market is open for innovation

A dual-power spring-piston breakbarrel

This is something people have long been asking for — an air rifle with two power levels. It already exists in air pistols. The HW 45 or Beeman P1 has been around for decades with two power settings. I have always thought that a rifle that develops 5-8 foot-pounds on the first cocking stroke and 15-20 foot-pounds on the second stroke would be nice.

M16 replica

There is no good copy of the M16/AR-15 in a pellet rifle. Crosman had the MAR177, a single-shot target upper that worked on an AR-15 lower. I actually built a lower to be able to test the MAR177. I wish I could have afforded one at the time, because it is no longer made.


Anschütz made a good airgun copy of the M16 years ago, but it was special order and not many people ever saw one. And my point is — there is  no accurate copy of the M16/AR-15 on the market today. The Crosman AIR17 wasn’t that close and while there are many airguns that resemble the AR today, there is no accurate copy.

M1 Garand replica

There was a replica of the 8mm Egyptian Hakim (the poor-man’s Garand) in 1954. But 66 years later there is no airgun replica of the rifle General Patton said was the “…greatest battle implement ever devised.” Oh, there are WONDERFUL airsoft replicas of it, but there have been accurate airsoft replicas of BARs and M60 machineguns since the 1990s! The airgunning world wants a Garand!


I believe 2020 will be a year when we see many new products. There will also be some refinement of existing products — the gen III guns I referred to earlier.

What I would like to see is more solid and innovative new designs like the Sig ASP20. When a company puts everything on the line and then nails the outcome, we all benefit — whether we buy their rifle or not. Because innovations like these set the standard for the entire market.

Gamo 126 single stroke pneumatic 10-meter target rifle: Part 2


by Tom Gaylord
Writing as B.B. Pelletier

Gamo 126
Gamo 126 single stroke pneumatic 10-meter target rifle.

Part 1

A history of airguns

This report covers:

  • RWS Basic
  • Sig Match Ballistic Alloy
  • RWS R10
  • Warmed up?
  • Second string of RWS Basics
  • Pump effort
  • Trigger pull
  • Discussion
  • Summary

Today is velocity day for the Gamo 126 target rifle we are testing. We learned a lot from the comments in Part 1 and I also learned a lot while researching the rifle for this report. Today we will see where this particular one is.

The Blue Book of Airguns said to expect a velocity of 590 f.p.s., but many owners say 550 is about as fast as they ever shoot and some even say less. The rifle also starts loosing velocity over time, so we should be able to assess the health of the gun I am testing right away.

RWS Basic

I will start with the lightest lead wadcutter anyone is likely to use — the 7-grain RWS Basic. I will warm up the action with several shots before starting to chronograph the results.

The first string of Basics averaged 434 f.p.s. The low was 415 and the high was 449 f.p.s. The spread from low to high was 34 f.p.s. I guess this 126 is getting tired again, following its reseal.

Sig Match Ballistic Alloy

Next to be tested were Sig Match Ballstic Alloy pellets They weigh 5.25-grains and should be the fastest that I test today. Ten of them averaged 496 f.p.s. The spread went from a low of 490 to a high of 501 f.p.s. That’s 11 f.p.s., so this pellet might be accurate. And the rifle may be warming up, so I need to test Basics again.


The next pellet I tested was the 7-grain RWS R10 Match Pistol pellet. I also tried a different way of pumping the gun. Instead of forcing the pump lever closed as fast as possible I went with a smooth motion that was decidedly slower. R10s averaged 454 f.p.s. with a spread that went from 449 to 460 f.p.s. That’s an 11 f.p.s. spread.

Warmed up?

It seemed like two things had happened as I shot this test. First, the rifle’s pneumatic mechanism had warmed up and second, the different way of pumping seemed to have given the shots more stability. So I wanted to try RWS Basics once more.

Second string of RWS Basics

This time 10 RWS Basics averaged 452 f.p.s. That’s faster than the fastest pellet in the first string (449 f.p.s.). So one or both of the things I said were working. The spread for this string went from a low of 432 to a high of 462 f.p.s., so a difference of 30 f.p.s. That is close to the 34 f.p.s. I got in the first string, so I think this Basic pellet is just not that stable in this rifle. But the rifle pump mechanism definitely did warm up a little!

Pump effort

The Gamo 126 and Walther LGR 10-meter target rifles both share a common flaw, in that their pump stroke is on the closing stroke when their levers move forward. This tends to make both rifles harder to pump than other single-strokes, though the Gamo has some kind of pump assist in its oil-filled piston and is actually easier to pump than any other 10 meter single stroke rifle.

The rifle I am testing requires 15 pounds of force to pump if you go steady and smooth. If you force the lever the effort spikes to more than 20 pounds. Only the awkward placement of the pump fulcrum at the rear of the action gives any hinderance at all.

Trigger pull

Now we come to the thing I am most interested in — the trigger pull. I told you in Part one that the 126 has a world-class trigger and now we will see how correct that was.

This is a two-stage trigger as all target triggers should be. I mean real target triggers — not just triggers that have the name target in their title. Stage one takes 3 ounces to complete and stage two breaks at 3.4 ounces. That’s an average of 5 pulls.


The powerplant in my rifle is not performing to spec. But it is fairly stable if I pump it correctly. I can live with that long enough to get through the accuracy test that comes next.


It seems that reader Geezer was right about the Gamo 126. It apparently does have performance issues. I always heard that it did, but now I know what they are and why they exist.

Does a 126 belong in a collection of vintage 10-meter target rifles? At this point I think it does — warts and all. But I still need to see the accuracy to know for sure.

Air Arms Pro-Sport: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

Air Arms Pro-Sport.

Part 1
Part 2
Part 3
Part 4

This report covers:

  • The inspiration
  • The kit
  • Installing this kit
  • Disassembly
  • Examine the parts
  • Factory top hat
  • Install the PG3 mainspring/li>
  • Spring guides very tight!
  • Assemble the piston and spring
  • Compression chamber is buttoned
  • Finished assembly
  • Discussion
  • Cocking effort
  • Firing behavior
  • Velocity with Hobbys
  • Additional benefit
  • Velocity with H&N Baracuda
  • Summary

Today is the day, airgunners. This is the day we open the .22-caliber Air Arms Pro-Sport we are testing and install a Vortek PG3 tune kit. It’s a drop in one-for-one replacement powerplant kit that promises to lower the cocking effort of the rifle and smooth out the shot cycle. The power output is 12 foot-pounds in .22 caliber which would be a 11.9-grain RWS Hobby leaving the muzzle at 674 f.p.s. And someone says, “Gee, BB, don’t you know you’re not supposed to tune for LESS velocity?”

Yes, I do. And this is exactly what I want. Even if I only get 625 f.p.s. with the Hobbys it’s what I want. Because I’m going for smooth — not power.

The inspiration

The initial inspiration was a Venom Mach II rifle that was owned by Trooper Walsh. That was the rifle that the Pro-Sport was built to copy, and it was a sheer delight to cock and fire. However, at $2,000 in the 1990s, it was an airgun I could never afford to own.

Then a few months ago I happened to shoot Jeff Cloud’s Pro-Sport. Once again it was a sheer delight to cock and shoot. It reminded me of the Mach II of my past. Only this rifle is still being produced, and at a far more affordable price. And Vortek makes the spring kit that tames the beast,

The kit

The kit consists of a new mainspring, a spring guide, a “top hat” that is a forward spring guide living inside the piston, two spacer washers, a small tub of grease and instructions.

Pro-Sport PG3 kit
The PG3 kit consists of a new mainspring, a white spring guide, a black “top hat” forward spring guide for inside the piston, two washers that can be used as spacers to increase the preload of the mainspring , a small (but way more than adequate) tub of grease and the instructions.

The instructions tell how to install the kit. There are several options that can be applied, and the instructions address them. They do not tell you how to disassemble the rifle.

Installing this kit

I found this kit very easy to install, but before you jump in with both feet, remember that I have been doing things like this for decades. What seems easy to me may not seem that easy to you. I do find Air Arms spring guns easier to work on than any other brand for several reasons. First, they are so well made that you seldom if ever encounter a problem from the manufacturer. Second, neither the TX200 Mark III nor the Pro-Sport require a mainspring compressor to safely open the powerplant.

I had never opened a Pro-Sport before this day, so what you are about to see was as new to me as it will be to many of you. But the Pro-Sport only differs from the TX200 in a few small ways that aren’t a hindrance, and I know TXs very well.


First remove the barreled action from the stock. This is straightforward, except that both of the triggerguard screws need to be removed and the triggerguard with them. Both screws are attached to the barreled action. The rear one attaches to the rear of the trigger unit.

To get the action out of the stock the underlever needs to be opened (not cocked — just pulled away from the barrel) to slip out of the cocking slot of the stock. Once the action is out you can open it by unscrewing one bolt. It’s the bolt that the front triggerguard screw attaches to. It has an 11mm head and comes right out, but here is a tip. If you want to find out how much preload the mainspring is under you can press the back of the end cap on the action against a padded place on your bench while unscrewing the bolt by hand (once it’s loose). The pressure you have to press the action down with to make this bolt loose enough to turn by hand is the amount of preload the spring is under. The factory mainspring took about 40 pounds of downward pressure to turn the bolt.

Pro-Sport bolt out
When the bolt is removed the trigger comes out. It’s pushed by the mainspring, and this is as far as it goes. This is why a compressor is not needed.

Slide the trigger out of the gun and then slide out the mainspring and spring guide, followed by the piston. Because the Pro-Sport has a sliding compression chamber, the piston is not held in the gun at this point. If it doesn’t slide right out it may help to pull the underlever down smartly and the piston should come sliding out.

Pro-Sport mainspring and piston
The trigger slides out and so does the mainspring and piston.

Examine the parts

I looked at the parts at this point. I expected to see perfectly machined and finished parts because this is an Air Arms airgun. I was not disappointed. The spring was lubricated with their grease in what looked like the correct amount. Their grease is thinner than the Tune-In-A-Tube I plan to use, so a lot of vibration should disappear when I install and lube the new spring.

Pro-Sport mainspring lube
Air Arms lubed the mainspring perfectly. But their grease is thinner than TIAT.

Factory top hat

A top hat is a forward spring guide that lives inside the piston. It is engineered to take up all the slack in the inner diameter of the mainspring, so it doesn’t vibrate on the piston rod when the gun shoots. It can also add significant weight to the piston, which makes the gun more efficient with heavier pellets. I could see a top hat inside the piston by shining a bright flashlight inside.

The Vortek kit comes with its own top hat, so the factory part must be removed. It didn’t just slide out, so I used a 4 by 4 wooden post and whacked the rod end of the piston down on the post to jar it loose. One rap was all it took.

Pro-Sport top hat
One whack of the end of the rod against a post was all it took to get the top hat (left) out of the piston.

Install the PG3 mainspring

The PG3 mainspring has a short black Delrin top hat (forward spring guide) on one end. That goes into the piston. But that part has three notches on its rim for the end of the mainspring to rest in. These three are at different heights, so each puts a different amount of preload on the mainspring. I selected the lowest notch to put the least amount of preload on the spring.

Pro-Sport spring in top hat
See the end of the spring in the rounded notch? That determines the preload on the mainspring. This is the lightest setting.

Spring guides very tight!

I must comment here that both spring guides are very tight on the spring. The black one that’s inside the coils needed padded pliers to turn it so the end of the spring could go into the right notch. The white rear guide goes around the outside of the spring and is also tight. There was just a bit of Vortek lubricant on that end of the spring. I removed it because I am lubing with TIAT.

Tight spring guides are an airgun tuner’s trick for removing vibration. They are more difficult to control in manufacture because coiled steel springs don’t like to hold tight tolerances, and in this case both the OD and ID of the spring have to be precise. So, I have a lot of respect for the PG3 kit!

Assemble the piston and spring

Now I tried to slide the piston and new spring back into the gun. It should slip right in, but for some reason it stopped at the entrance to the sliding compression chamber. I fiddled with it for a minute and couldn’t get it to slide in, so I removed the sliding compression chamber to slide the piston into it outside the gun. Just one Allen screw connects it to the cocking linkage.

Pro-Sport Allen screw
Just one Allen screw (arrow) holds the sliding compression chamber inside the rifle. Remove it and the chamber slides right out.

Compression chamber is buttoned

I was surprised to see three button bushings at the front of the compression chamber. They keep the front of the chamber centered in the spring tube and offer little resistance to the chamber sliding when the rifle is cocked.

Pro-Sport chamber
The Pro-Sport sliding chamber (bottom) has three button bearings around its circumference to center the chamber in the spring tube. The smaller hole on the right is for the Allen screw.

Finished assembly

Once the chamber was out of the gun I was able to insert the piston into it and then slide everything back into the gun. The new mainspring is shorter than the factory spring, so there was even less preload on the end cap when I inserted the bottom bolt.


It took me a total of 40 minutes to install this kit, start to finish. At least 15 of those minutes were spent taking pictures. I had to wipe my hands before handling the camera for each photo And, when I say start to finish I mean starting with an untuned rifle and finishing by shooting the rifle after the installation. You always test a spring gun by shooting it after the tune because sometimes the parts aren’t in correctly. Shooting is the only way to find out.

The rifle fired the first time and I knew I had hit the nail on the head. It now cocks with much less effort and fires very smoothly.

Cocking effort

The factory-tuned rifle cocked with 48 pounds of force. Not only is that a lot, the fulcrum of the underlever is located in a place that makes working the underlever particularly difficult.

After the PG3 kit was installed the cocking effort is reduced to just 35 pounds. It’s still not light, but it’s far easier to cock this Pro-Sport now than before.

Firing behavior

The Pro-Sport is now calm when it fires. The factory rifle buzzed a little, but that is all gone, as I knew it would be. The TIAT guaranteed the buzz would leave, and the tightness of the PG3 parts assured me that I could use the TIAT sparingly. This rifle is now a delight to shoot!

Velocity with Hobbys

And now for the big test. I chose the RWS Hobby to test the rifle. In factory trim the Pro-Sport launches Hobbys at 760 f.p.s., which is good for 15.27 foot-pounds at the muzzle. The spread was 13 f.p.s.

As the rifle is now tuned the Hobby averages 633 f.p.s. for an energy of 10.59 foot-pounds at the muzzle. The spread of the 10-shot test string went from 628 to 639 f.p.s, a difference of 11 f.p.s.

Additional benefit

Not only is the Pro-Sport now easier to cock, it sets the safety every time. Because the cocking effort is reduced, the lever pushes the piston far enough back to set the safety without fail. It even set when I conducted the cocking effort test on the scale.

Velocity with H&N Baracuda

On my velocity test with the factory spring the H&N Baracuda pellets with a 5.50mm head were the most powerful, when they should have been the least. All things being equal, a lighter pellet produces more muzzle energy than a heavier one in a spring gun — or at least that is how it used to be. But the factory top hat I removed from the piston was weighted, which made the piston’s weight greater, and I felt this gun was made to shoot heavier pellets.

Since I removed that heavy top hat and replaced it with a Delrin one that has very little weight, I guessed the Baracuda pellet would no longer be more powerful than the Hobby. To produce 12 foot-pounds this 21.14-grain pellet has to travel 506 f.p.s. I guessed it would average around 475 f.p.s., which is good for the same 10.59-foot pounds as the Hobby. But that was wrong, too. With the PG3 tune as I applied it Baracudas now average 437 f.p.s., which is good for 8.97 foot-pounds. The spread went from a low of 433 to a high of 443 f.p.s. with is 10 f.p.s.


This Vortek PG3 tune kit did exactly what I wanted. The Tune-In-A-Tube slowed things down below the 12 foot -pound spec, but I couldn’t care less. I finally have the sweet and mellow Pro-Sport I was after!

The next step will be to mount the Meopta MeoPro Optika6 3-18X56-scope and see what she can do. I have very high expectations! After that — who knows?