[Stinkyshoe]

Will this cause any problems? Will the upper and lower match? Will there be any wear problems? Anything you can tell about this would be appreciated.
Thanks
Ss

[Steve Smith]

Everything should match just fine, unless the Colt lower was for the "big pin" Colts...something only they did. If so, I think someone makes an adapter pin for it.

[Kristofer]

You can order the offset pin from bushmaster for $5. I just got a bushy M4 upper for my colt lower. Except for a slight color difference, everything is the same.

[Redlg155]

If you have a sear blocked Colt lower will also have to get a Colt type bolt carrier. Either that or have the sear block removed.

Good Shooting
Red

[JimC]

I have an '86 vintage Colt AR-15 A2 HBAR. I purchased a BM A2 M4 config. upper last year along with the offset pin and it worked like a dream.

I have since changed the A2 upper to an A3 config. but use the same Colt lower and again, with no problems at all.

Slight color difference but I don't care.

[Watch-Six]

It will work fine. Most Colts have the large diameter front screw that will require the adapter screw. Some Colts have the normal push pin and will work as is. Either way it is no big deal. Watch-Six