by Tom Gaylord
Writing as B.B. Pelletier

Part 1

Air Venturi V10 pistol
Air Venturi’s V10 Match pistol.

This report covers:

  • R10 Match Pistol
  • H&N Finale Match Light
  • Sig Match Ballistic Alloy
  • Discussion
  • Cocking/pumping effort
  • Trigger pull
  • Surprise!
  • What’s happening
  • Summary

I was surprised by the amount of interest the Air Venturi Match pistol generated in Part 1. A lot of you are interested in it, so besides reviewing it in the usual fashion I’m going to show you some things about this pistol and about single stroke pneumatics in general that aren’t widely known or discussed.

Today is velocity day, so I will begin there. Because this is a target pistol I’ll test it with target pellets. It’s rated to 400 f.p.s., so let’s find out what this one does.

R10 Match Pistol

I’ll begin with the RWS R10 Match Pistol pellet that is often extremely accurate in target air pistols and even in air rifles of lower power. In the test V10 they averaged 379 f.p.s. for 10 shots. The low was 377 and the high was 383 f.p.s., so a total spread of 6 f.p.s. Single stroke airguns are usually very stable, so this low spread is not surprising. At the average velocity this pellet generated 2.23 foot-pounds of energy at the muzzle.

I will say the R10 pellets I used fit the V10’s breech very tight. I didn’t know what to make of that.

H&N Finale Match Light

The second pellet I tested was the H&N Finale Match Light pellet. The pellets I linked to weigh 7.87 grains, but the pellets I shot were older and weigh 7.5 grains. I weighed several and they were all that weight. In the V10 they averaged 366 f.p.s., with a spread that went from a low of 357 to a high of 370 f.p.s. That’s a range of 13 f.p.s. At the average velocity this pellet produced an identical 2.23 foot-pounds at the muzzle. And these also fit snug, though not as tight as the R10s.

Sig Match Ballistic Alloy

The last pellet I tested was the Sig Match Ballistic Alloy target pellet that weighs just 5.25 grains. We know that being lighter will make this pellet go faster, but we also acknowledge that this target pellet in one of the most accurate pellets we have tested in lower-powered airguns across the board. So this isn’t just a bragging-rights test. In the test pistol they averaged 412 f.p.s. with a spread that went from 399 to 417 f.p.s. That’s a range of 18 f.p.s. At the average velocity this pellet generated 1.98 foot-pounds at the muzzle. These were snug but not tight in the breech.

Discussion

The test pistol is about where I expected it to be, in terms of velocity. Now I will test the cocking effort and the trigger pull, because that is what I do in a part 2 report. Then I have a surprise. Something different that will help all owners of single stroke pneumatics.

Cocking/pumping effort

Single strokes are cocked and pumped at the same time. What would be the cocking effort in other airguns is really the pumping effort in an SSP. Of course, by their nature these guns are only cocked/pumped once per shot. It’s not like a multi-pump where there are different efforts for each pump stroke.

So — what does it take to pump this one? To test the effort I opened the pistol them laid the top of the gun on a bathroom scale and pressed down on the bottom half until the gun closed. The effort ranged from a low of 20 lbs. to a high of 23 lbs. and I could control it by how hard I pressed down. If I wanted it as low as possible I simply did not press down as hard and allowed more time for the pistol to close. If I wanted it to go higher I rushed it. That is a “secret” of pumping single strokes that you can apply to your guns.

Trigger pull

Now let’s measure that trigger pull. Using an electronic scale I measured stage two at between 2 lbs. 2 oz. and 2 lbs. 9 oz. Stage one was a uniform 12 oz.

There is an adjustment screw on the back of the grip near the bottom. I adjusted it in both directions for 15 minutes and all I did was make the pull heavier. When I finished the trigger pull was 2 lbs. 14 oz. I did establish that turning the adjustment screw counterclockwise, like the manual says, does increase the pull to over 3 lbs. I just never was able to get it lighter than 2 lbs. 10 oz. after starting to adjust.

V10 trigger adjustment
The trigger pull adjustment screw is in a deep hole at the bottom rear of the grip.

In the next report I plan to show you a secret about this trigger. And I hope to reduce the pull at that time.

Surprise!

Okay, here is today’s surprise. I reshot all of the pellets a second time. I shot each one three times. Let me show you what happened.

Pellet………………….Velocity
RWS R10 Pistol
Average before…………..379

Shot 1……………………396
Shot 2……………………403
Shot 3……………………402

H&N Finale Match Light
Average before…………..366

Shot 1……………………388
Shot 2……………………395
Shot 3……………………388

Sig Match Ballistic Alloy
Average before…………..412

Shot 1……………………458
Shot 2……………………455
Shot 3……………………450

Whaaaaat? How is this possible?

It’s simple. I just softened and heated the pump head before taking each shot this time. This is something I did on the first year of American Airgunner with my tired old IZH 46 pistol. I showed the viewers how to renew their single stroke pneumatic pump cups by how they pumped their guns.

Here is how I did it. I loaded a pellet then pushed the top strap halfway down to closure and then released it again six times. I could feel the pressure building on each abbreviated pump stroke. Each time you do that the pump cup flexes as it fills with air. Do it several times in a row and the pump cup gets warm and softer. It then seals much better when you complete the pump stroke on the 7th try. There is no magic in the 6 tries. You will get results from doing it any number of times.

I initially did this to rejuvenate my old IZH 46 pump cup, but it works for all single strokes. Try it! Oh, you will need a chronograph.

What’s happening

The pump cup or head on a single stroke pneumatic is soft and flexible enough to expand quickly when the gun is pumped. Not only does it compress air, when it ends up at the end of the pump stroke it also seals the compressed air in front of it. There is no special inlet valve doing this — just the pump head. That’s why it’s recommended to shoot the gun soon after pumping, so the head doesn’t remain under pressure, because as flexible as it is, it can’t stand the pressure very long.

When the pump cup gets old the material it’s made of hardens and isn’t as flexible. This little drill will rejuvenate it for a short while. To find out how long the effect lasts, I tested the gun again with the same pellets. This time I just pumped it like normal — no half-pumps. No more than two minutes had passed since the previous test with half-pumps.

Pellet………………….Velocity
RWS R10 Pistol
Average before…………..379
After the half-pump test…380

H&N Finale Match Light
Average before…………..366
After the half-pump test…370

Sig Match Ballistic Alloy
Average before…………..412
After the half-pump test…430

So, immediately after the drill of warming the pump cup, the velocity has returned to nearly normal, when the gun was pumped and fired as usual. That demonstrates that if you want the higher velocities you need to do the half-pumps on every shot.

Summary

That’s it for today’s report, but we are not done with the pistol yet. Before we move to accuracy, I want to show you what can be done with the trigger.