Lothar Walther barrel | Air gun blog

Testing the effect of barrel length on a precharged rifle

Posted on August 20, 2013 by B.B. Pelletier ↓ 43 Comments

by Tom Gaylord, a.k.a. B.B. Pelletier

This test was done for blog reader GunFun1, who asked to see what effect barrel length has on velocity. Though it appears simple, this test took 2 days to conduct because of barrel changes and other sundry things. But what was learned far exceeded my hopes, so the effort it took was well worth it.

Conduct
I tested with an AirForce Talon SS, which has the facility to accept interchangable barrels. All testing was done with the rifle in .22 caliber, which means every barrel used was that caliber. I used the factory-installed 12-inch Lothar Walther barrel, an optional 18-inch Lothar Walther barrel and an optional 24-inch Lothar Walther barrel.

How does rifling twist rate affect velocity and/or accuracy? Part 13

Posted on July 24, 2013 by B.B. Pelletier ↓ 33 Comments

by Tom Gaylord, a.k.a. B.B. Pelletier

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Part 2
Part 3
Part 4
Part 5
Part 6
Part 7
Part 8
Part 9
Part 10
Part 11
Part 12

This is the summary report in this series. I’ll give you my thoughts on how this test went, and I expect you to comment, as well.

The barrels
Three barrels were used in this test. One was the factory barrel that comes with the .22-caliber AirForce Talon SS. It’s a 12-inch Lothar Walther barrel that has a choke of about a half-thousandth inch reduction in the bore diameter for the final 2 inches of length. That makes all the pellets of uniform size as they leave the muzzle, and it may potentially stop any in-bore wobble. This barrel has the standard airgun twist rate of 1-turn-in-16-inches of bore travel, written as 1:16″.

How does rifling twist rate affect velocity and/or accuracy: Part 12

Posted on July 9, 2013 by B.B. Pelletier ↓ 68 Comments

by Tom Gaylord, a.k.a. B.B. Pelletier

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Part 9
Part 10
Part 11

Today, I’ll report on the final test in this series. This isn’t the final report — just the final test, which is the barrel with the 1:12″ twist, shooting at 50 yards. Get ready to be surprised. I know I was!

I did this test on the same perfect day as the factory barrel that was reported last week in Part 10, and the weather was perfect most of the time. From time to time, there was a very slight breeze that I waited out before shooting. The shooting conditions were as good as they get.

Changing barrels took 5 minutes. The silver barrel has the 1:12″ twist.

How does rifling twist rate affect velocity and/or accuracy? Part 11

Posted on July 3, 2013 by B.B. Pelletier ↓ 41 Comments

by Tom Gaylord, a.k.a. B.B. Pelletier

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Part 10

Continuing our look at the 3 different twist-rates, today I’ll shoot the factory Lothar Walther barrel at 50 yards. The factory barrel has a 1:16″ twist rate that has become ubiquitous for airguns and is the very thing this test is designed to examine. Last time we looked at how the 1:22″ twist barrel did at 50 yards, with 2 different pellets fired at power levels 6 and 10. Today, we’ll see the same thing with the factory barrel.

This test was performed yesterday, and the range conditions were perfect. There wasn’t a breath of air to be felt for most of the shooting session, and only an occasional puff of air later on in the morning after I swapped barrels for the final test. I’ll report on that set of results in the next report. Today is devoted to the factory barrel.

How does rifling twist rate affect velocity and/or accuracy? Part 10

Posted on June 26, 2013 by B.B. Pelletier ↓ 39 Comments

by Tom Gaylord, a.k.a. B.B. Pelletier

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Part 9

Today, we’ll begin looking at the effects of the rifling twist rate on the accuracy of our test AirForce Talon SS rifle in .22 caliber at 50 yards. If you’re prone to jumping to conclusions before all the data is in, I have to caution you that today’s test will look bad because I’m testing the custom barrel that has the 1:22″ rifling twist. We know from the earlier tests that this barrel was most accurate at 10 meters on power levels zero and 6. Above that power level and also out at 25 yards, the accuracy of this twist rate broke down. So, it would be reasonable to assume that this barrel will give results that are even worse at 50 yards.

How does rifling twist rate affect velocity and/or accuracy? Part 9

Posted on June 18, 2013 by B.B. Pelletier ↓ 42 Comments

by Tom Gaylord, a.k.a. B.B. Pelletier

Before we begin, there was a request last week for me to test the Benjamin 392. I thought I’d tested it already, and it turns out I did. Click see all 5 parts on the old blog.

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Part 3
Part 4
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Part 6
Part 7
Part 8

The question of barrel equivalency
Today, we’ll look at the accuracy side of this test, where yesterday we looked at how the twist rate affects velocity. Before I begin, however, we have to settle an issue that’s in a lot of people’s minds. Namely, is it reasonable to test barrels made by Dennis Quackenbush against a Lothar Walther factory AirForce barrel? Will the test results be skewed for that reason and not because of the different rifling twist rates? Or will the twist rates determine part of the results and the barrel’s pedigree determine the rest?

How does rifling twist rate affect velocity and/or accuracy? Part 8

Posted on June 17, 2013 by B.B. Pelletier ↓ 30 Comments

by Tom Gaylord, a.k.a. B.B. Pelletier

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Part 2
Part 3
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Part 5
Part 6
Part 7

Today, I’m presenting the first part of the data collected thus far in this extensive test. My thanks to blog reader Fred DPRoNJ (Democratic People’s Republik of New Jersey)for creating the original spreadsheet for this data. Although I didn’t use his spreadsheet in the publication, I did use it as my worksheet to put this report together. Thanks, Fred!

This is a look at how the twist rate of rifling affects the velocity and accuracy of pellets in an AirForce Talon SS rifle in .22 caliber. We’re testing the same 2 pellets in each of 3 different barrels in the same gun. All 3 barrels are the same 12-inch length. Two of the barrels were custom-made by big bore airgun designer/maker Dennis Quackenbush for this test, and the other barrel is a factory Lothar Walther barrel that comes with the rifle. I chose this airgun for two reasons. First, it allows the quick barrel change that makes this test possible. Second, it has adjustable power so we can vary the power for each pellet we test.