Not new to ARs by any means, but I have never "cross-bread" one before......

I have a BM A2 20" that I'm wanting to go to a shorter barrel and A3 upper.  I have found a used but clean DPMS upper @ what I think is a "buy".  I've heard that some of the early Colts have different hinge/ retaining pin sizes than newer ARs and require an offset pin to fit.  I see alot of manufactures calling their equipment "milspec", but some do not.  I know that companies are constantly trying to win government/ military contract bids, so I can see why they would make thier parts interchange.

In short.......will the DPMS upper fit my BM lower and most any manufacturer's barrel that I may choose without any hitches.  I would like to have a "pin and run"setup.....if possible.

Any and all advice will be greatly appretiated.

Thanks in advance,
DFA

yes, colt is the only one with the odd ball pin sizes

So....they would fit, but will they function fine together???  MilSpec???

Thanks,
DFA

they will work just fine. 100% go shoot them






Invisiblesoul