Pellet velocity versus accuracy test: Part 6

by B.B. Pelletier

Part 1
Part 2
Part 3
Part 4
Part 5

For the benefit of readers who have landed on this article first, this is the sixth test in a series of reports designed to test how velocity affects accuracy. I’m using a Whiscombe JW75 breakbarrel/underlever rifle with a .177-caliber barrel installed. That way the same powerplant is being used for each test. I’m controlling the power of the gun by the use of different air transfer port limiter screws that allow less and less air to past through.

The Whiscombe rifle uses dual opposed pistons that come together to compress the air when the gun is fired. The rifle has no recoil and just a minor impulse that can be felt — yet it’s one of the most powerful spring-piston air rifles ever made. My rifle can produce over 30 foot-pounds in .25 caliber. read more


Pellet velocity versus accuracy test: Part 5

by B.B. Pelletier

Part 1
Part 2
Part 3
Part 4

Today we look at the groups made by the four pellets used in this test at 25 yards when the velocity is diminished. Part 4 covered the velocity for each pellet, so go there to see where each one is.

If you like nice linear results, prepare to be disappointed. Today’s target do show changes, but they may not be in the direction you expect. Let’s get right to it.

First up were the 7.1-grain Beeman Devastator pellets. These pellets have been a real surprise in this test, because they have proven to be accurate at supersonic velocity and they are not sensitive to bore conditioning. Shoot one and it tends to go to the same place every time. They also do not show any first-shot tendencies that so many other pellets do. This is a real plus for hunters, who are always shooting the first shot. I will have to return to this pellet sometime soon and test it in other guns, because it seems to be a real winner. read more


Pellet velocity versus accuracy test: Part 4

by B.B. Pelletier

Part 1
Part 2
Part 3

Today we lower the velocity of the Whiscombe and test each of the four pellets, in preparation for the next accuracy test.

One reason I selected the Whiscombe for this series of tests is the fact that I can control the power output over a wide range of velocities by installing various transfer port limiters. For those who are new to airgunning, every spring-piston airgun like the Whiscombe generates a brief blast of compressed air by means of a piston racing forward in a compression tube. In the Whiscombe’s case it is actually two pistons racing towards each other. At the exact end of their travel a small air tunnel called an air transfer port conducts the compressed air from the compression chamber to the base of the pellet, where it blows it out the bore. read more


Why do you need a scope level?

by B.B. Pelletier

I’m writing this report because I saw from the comments on the accuracy versus velocity test that several readers do not know what a scope level does. And where three people speak out, there are three hundred who are reading and remaining silent.

They say that there’s nothing more zealous than a convert, and I expect that is true of me when it comes to scope levels. I have understood their need for a long time and even conducted a fairly extensive cant test back in my Airgun Letter days, but it was my .38-55 Ballard single-shot rifle that really drove the message home. That rifle came with a bubble level, and it’s far more precise than the levels we find on air rifles today. The bubble moves very slowly, making it important to check the level just before you begin the squeeze; because what looks like a level gun one moment can change slowly to a canted gun if you don’t watch the level. By contrast, the scope levels I’m using with airguns have bubbles that move very fast, are much easier to see and are far simpler to work with. read more


Pellet velocity versus accuracy test: Part 3

by B.B. Pelletier

Announcement: Jerry Strong is this week’s winner of Pyramyd Air’s Big Shot of the Week on their facebook page. He’ll receive a $50 Pyramyd Air gift card.


Jerry Strong, winner of the Big Shot of the Week, holds a Stoeger X50 and wears a Beeman P1 on his hip.

Part 1
Part 2

What a day we have before us! I relearned a valuable lesson in accuracy and got some very surprising results.

Increasing accuracy by an order of magnitude
Before I launch into today’s report, a comment I made a few days ago has raised some interest and I thought I would explain it now. I happened to mention that a new loading technique that I was trying on the Ballard .38-55 rifle had given me the promise of an accuracy increase of an order of magnitude. Instead of 10 shots going into one inch at 100 yards, it looks like this new technique will be capable of putting those same 10 shots into one-tenth of an inch at the same distance. Whether I ever accomplish such a feat is immaterial as long as the rifle demonstrates it can do it. read more


Pellet velocity versus accuracy test: Part 2

by B.B. Pelletier

Part 1

Today, I’m testing the accuracy of my Whiscombe running at full bore. This is the end of Phase One of this experiment. Next time, I’ll reduce the velocity of the rifle and retest all four pellets.

The shooting was done indoors at 25 yards. The Whiscombe is scoped with a Simmons 4-12x scope, and I did use the artillery hold, even though the rifle is recoilless, because John Whiscombe told me to.

Beeman Devastators
KRAAK! That’s what the Beeman Devastator pellet says when it goes downrange at 1,200 f.p.s. It sounded as loud as a .22 long rifle shot, though I’m sure it wasn’t.

I was all set to show you a blown group and then lecture you about the evils of diabolos breaking the sound barrier, only these pellets didn’t seem to cooperate. They all wanted to go to the same place, which upsets all sorts of apple carts. read more


Pellet velocity versus accuracy test: Part 1

by B.B. Pelletier

Welcome to the test that blog reader Mel inspired last week when he made the following comment about whether pellet guns can be overbore:

I live in Germany, where all airguns are limited to 7.5 joules (5.6 fpe). This is very annoying for long-range shooters and also limits the choice of airguns, as many models are not offered in low-powered versions. But the big advantage is that the beginners here get an airgun they can actually shoot precisely, while so many Americans buy one of these $200, 1600 fps bangers just to become disappointed because it acts like a supersonic water hose.

Ask yourself how much power you really need and have a look at the Brits that hunt anything up to rabbits with 12 fpe. I personally would never sacrifice accuracy or comfort to exceed these 12fpe, unless I had a really good reason for it. read more