I live in CA, due to dumb inexplicable laws I cannot use a flash hider, I couldnt find a .458 socom muzzle brake so i bought a .308 muzzle brake.
the biggest drill bit i had was .470 my boolits are .452 this is for a .45 acp ar15 upper.
not big enough? don't want to take the risk of blowing off the end of my muzzle and threads.