Does Bushmaster stamp the model of an upper somewhere on the barrel or upper receiver?  I have what I think is a 20in" PostBan National Match A2 upper that I want to sell, but I want to make sure that it is exactly what I think it is so that I'm not advertising it incorrectly.  I'm guessing that is what it is from looking at Bushmaster's website and comparing the pictures to the upper.

I don't have the specifics because I bought the rifle that this upper came off of from a private seller and I didn't get any paperwork with it.  

Also, it has a compensator on the front end.  How do I know if it is "pinned" or "welded" or affixed in some other way?  It has 9 holes on the top in a 3 by 3 pattern, and then three larger holes on both the left and the right.  Maybe someone who is familiar enough with the compensators available might be able to tell the manufacturer from that description.

Well, does it look like this?


This is a Y-Comp that Bushmaster put on a lot of rifles during the ban.

Does your barrel have any marks on it?

WIZZO

EDIT: You can also go HERE at Bushmaster and look at the brakes they have to see if any look familiar.

The upper receiver itself will not have any distinguishing marks on it, other than maybe some light gray dry lube inside the receiver.

The barrel should be marked something very similiar to "B MP 5.56 NATO 1/9 HBAR".  If the barrel isn't stamped similiar to this, it's not a Bushmaster.

Wizzo showed you one of the muzzle brakes that Bushy installs, the Mini-Y.   There are some others, like the Izzy and such.