[Skofnung]

Do any of you know what the optimum barrel length for a .22 long rifle is? What I am asking is, how long does a barrel have to be to get maximum velocity out of the bullet?

I know this will vary between certain cartridge types, but I am looking for a ballpark average.

Thanks

[Brian Williams]

about 16" to 18"
but do not cut it shorter than 16
ATF is everywhere

[Skofnung]

Oh, I know. I am not planning to cut anything.

I was thinking of backboring a cheap old bolt action .22 just to see what would happen. I want to bore it back to the optimum barrel length.

I have heard (possible that it is not true) that by doing this, the gun A) makes less noise, and B) aids in accuracy. I have access to a machine shop and I have done a few things like this before.

Have any of you tried this before?

Thanks

[Andrew Wyatt]

12 inches is the optimum.


I don't think backboring it will fly with the ATF.

[Archie]

Sixteen to eighteen inches will use all the powder and pressure available.

Check with ATF about the backbore idea. Length of barrels include stuff like permanently mounted muzzle brakes and such, so I don't think the amount of rifled barrel matters.

It might be interesting to see how the length effects velocity as you shorten the rifled section of bore.

Oh, don't mention the quieting effect to ATF. They might charge you (as in excise tax) for manufacturing a silencer.

[C.R.Sam]

Have seen a few match guns with quite a bit of back bore.
Keeps max legal sight radius and optimizes actual barrel length.
Supposedly.

Sam

[Andrew Wyatt]

in 7th grade, i charted the velocity/barrel length curve in excel for a science project. 12 inches is the optimum.


you can do this at home by chronoing a bunch of different barrel lengths of .22s, inputting the data into excel, making a chart, and doing a regression on it. (IIRC)



IF you want, i can do that again. I just need velocity data from a couple different barrel lenghts of .22, using the same ammo.

[Sodbuster]

I've read several times that 16" is about right. The last time I read this was in Peterson's RifleShooter magazine, Sept/Oct 2003, pg. 61, in an article by Wayne van Zwoll. At any rate, you don't need a 22" barrel like I have. :)

[Futo Inu]

about 12".

Go with 16.1" if you don't want to mess with fed regs.