Q: Smith Vortex in 5.56; use in 7.62; Bored-out ??

[OneBarfly]

OK: I already have a M305 barrel cut down and threaded for a 1/2"-28 flash elliminator. I have heard some people say that the .556 Votex F.E. will need to be bored-out to accomdate a 7.62 dia bullet.

Does anybody know this for a fact? Does anybody have the inside dimensions for the vortex 5.56 vs. 7.62?

Anyone know what the minimum I.D. of a .30 caliber flash hider or muzzle break should be?

I remember years ago, Smith Enterprises told me that the ID of the brake measures .340 to .343; Thoughts?

 

[Kano]

A 5.56 FH will need to be bored out. Or you could look into an AR10 style FH that would already be .308.

http://www. brownells.com/aspx/ns/store/ProductDetail.aspx?p=18711&title=AR-15%2fM16%2fAR-STYLE+.308+G6-A2+VORTEX+FLASH+HIDER

 

[Craftsman 441]

If you try to fire a .308 bullet through your 5.56 vortex you may have trouble with a follow-up shot.

Chuck the FH in a lathe and drill it out with an 11/32" (0.3438") or R (0.3390") drill. With the one on my M14S, I went a step further and reamed it with a S size reamer. Letter size S is 0.3480" giving the bullet 0.020" of clearance in every direction. That is plenty of clearance, plus it keeps carbon, copper and other crap from collecting between my crown's chamfer and the flash hider.