POF 11.5 with a krink brake question
I have a POF with a 11.5 inch barrel and krink brake. I undid the brake and found that the barrel is huge and the threads are definelty not 1/2 by 28. So I want to put on a AAC M4-2000 mount, is this possible? Or since I bought the upper with the krink brake I am stuck with those huge threads. Thanks guys this is myfirst piston upper.
Does anybody know? I took a look at the threads, and there are two narrow slits on each side making me think it might be removable with the right tools.