View Full Version : FH inner diameter for .45 ACP?

June 20, 2007, 16:16
I have a .45 acp barrel, lo and behold it is threaded the same as an AR-10, so I opt for the Vortex I have laying around that is the correct thread, of course its .30 cal, so I bore it to .470. is this enough for a .45 ? I could go to .483 or .490. so far it looks as though nothing will touch, but it is damn close. Any ideas?

June 21, 2007, 09:11
My understanding is that muzzle devices are normally bored a minimum of .020" over bore diameter. Especially with a brake, it has to be close to do any good. I'd say try it as-is; fire a few rounds and then check for any evidence of bullet strikes. If the bullets are striking, open it up a bit more and try again.

The critical factors are if the bore is centered in the barrel (frequently NOT the case), and if the threads are straight (also frequently not the case).

June 21, 2007, 09:36
well a flash hider isnt going to do anything for ya any way ,,,as far as compensation ..wont matter what size over the bore it is for a fh ...
usually .005 per side is standard clearence for real comps ....

June 21, 2007, 19:57
it does one thing, its only job as far as I care, it hides threads, plus it looks cool. Get to use a part I had laying around. I would say I am getting about .010 max clearance any side, so it should be ok if everything else was centered, its just a pain to get it bored out again for me, got to go begging navy machinest to do it if it doesn't work out. But I think it will. Thanks guys.

July 01, 2007, 21:21
After firing, no evidence of tipping. or flash, like there would be alot from a 16 inch .45? but it worked. and still looks good too.. ;)