Best length 9mm barrel for new AR Pistol build. [Archive]

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PA PATRIOT

09-19-14, 11:58

I know there is a lot of different burn rates of pistol powder that the manufacturers use in a 9mm standard and +P loads and that temperature has a additional effect also. But I was wondering if anyone ever did a study using commercial 9mm ammunition both standard and +P to determine the optimal pistol barrel length for velocity only.

Thanks!

Clint

09-19-14, 22:14

Have you seen this site?

http://www.ballisticsbytheinch.com/9luger.html

RHINOWSO

09-26-14, 23:37

IMO, there is minimal gain beyond 6". I have a 5.5" AR SBR that is DA bomb.

DWood

09-27-14, 11:39

Nnge.and .OTE=RHINOWSO;1996522]IMO, there is minimal gain beyond 6". I have a 5.5" AR SBR that is DA bomb.[/QUOTE]

I have read that a barrel five inches or less will keep 147 grain rounds subsonic. I went with a four and a half inch barrel and my muzzle device will be a suppressor. I hope to finish the lower this week and get it to the range.