Minimum Barrel Length For .22 Mag?

[mmattockx]

I have seen a number of threads that indicate a 16" barrel will produce max velocity using .22LR. Has anyone seen the same info regarding the .22WMR?

Thanks,
Mark

 

[Longwalker]

longer is better. No max.

 

[SCDL]

longer is better. No max.

There has to be a point where friction from the barrel will outweigh the expanding gasses.

 

[Longwalker]

yes there is, but it is likely something over 26" so, I'll revise my comment: no practical max.

 

[SCDL]

I'd still be curious to know what it is, but I'll agree that you probably won't reach it with any common rifle.

Also, I would like to add that 40 grain FMJ .22 WMR, even out of a 2" revolver will meet FBI penetration standards.

 

[guntech]

Quite a discussion about this on Benchrest Central a while ago.

benchrest.com/forums/showthread.php?t=65968 (copy and paste into your own www )

The following information is from Mark White's book "The Ultimate Ruger 10/22 Manual and User's Guide" . Apparently, he cut a 28 inch barrel two inches at a time and measured for muzzle velocity.

Ruger 77/22; Remington Standard Velocity .22 LR ammunition
Barrel Length/ Velocity
28 1095
26 1107
24 1119
22 1129
20 1138
18 1149
16 1157
14 1149

So, based on this (that ammo and that gun), it would seem maximum velocity in a .22 is acheived at 16" with a loss of about 5 fps/inch over the next 12 inches.

 

[mmattockx]

So, based on this (that ammo and that gun), it would seem maximum velocity in a .22 is acheived at 16" with a loss of about 5 fps/inch over the next 12 inches.

Yeah, but the magnum is loaded with slower powders to take advantage of longer barrels. That test is the one I was mentioning regarding the standard .22LR round, thanks for the link.

Mark