Gas Port Size for 12" unsupressed barrels?

[wideglidejoe]

There have been many reports of Ballistic Advantage 12.5” barrels being under gassed because the gas ports were to small. BA assumed most users would use suppressors and tend to be under gassed without a suppressor. The Faxon 12” Group Buy barrels with carbine length gas port were .068”. I’ve read where some BA owners used .070” or a little larger port to get reliable functioning without a can.

Temperature and ammo can contribute to short cycling with a new upper. After the upper wears in your gas port might be gtg. I think I’d try some other factory ammo before I pulled the gas block. You can use drill bits to get pretty good measurements on size of the port if you don’t have calipers.

I have a 12.5" BA barrel, with the same issues you stated sharpshooter33. I called BA, they told me the same thing VASCAR2 said, they assumed it would be used w/suppressor. They said my barrel should have left the factory with a .055" port, I measured it as .050", I drilled it to .073" and it runs great w/o a suppressor.