hey guys
i have a colt hbar match target i picked up on a trade a while back
556 1in7 twist with sear block and that funky front pivot screw that is almost impossible to find and has no hole for detent or spring
it doesent have a flash suppressor on it nor does it have threads my question is what size tap would i use to be able to mount a flash suppressor?
i shouldave miced the bbl first before posting but had the thought before i could dig it out
i would realy like to take it out to the range but the muzzle blast sucks!
any help would be great!

if i get a chance this weekend ill dig it out and mic it and post dimensions
