looks to be a tec 9 barrel extension on a mac 10. don't see that often. any gun experts care to comment?
Doesn't have to be a tec 9 barrel, Looks like just an open port barrel that came with that mac 10 or mac 11, Just reduces recoil when fired. Sorta like a muzzle brake on an ak or ar etc. Hard to tell if an 10/11 diff from this pic. Mac 10 are more exclusive now days & mac 11 aren't hard to get a hold of at all. Most likely it in a 9mm by size of the mag & they are more common in 9mm then 45acp. I'm not an expert but I love guns so theres my input.