9mm Colt AR

AR/M4 AR Technical Discussion
1

I’ve got a 9mm Colt AR and it came with the fixed carry handle…Can i buy a flat top upper receiver from Colt and swap barrell and such over to make a flat top out of the exhisting parts. Or any quality upper receiver for that matter… Thanks

2

Sure can. The only real difference is the 9mm Brass deflector and cut down dust cover. They’re nice to have, but not essential to operation.

3

That’s not 100% accurate.

A 9mm upper forging lacks the gas tube hole (for obvious reasons) as well as the integral brass deflector and forward assist.

RRA sells a correct 9mm upper that you can find from retailers in the <$150 range.

4

I got rid of the plastic brass deflector on my 6450 and I haven’t noticed any functional difference (although I’m right-handed).

5

Thanks everyone for the replies…And a special thanks to Rob for the 6933 recommendations…My dealer here in SC just received my 6933 from Clyde’s and i’m in the process of getting my paper work completed and sent off.

6

A standard Colt flat-top upper receiver works just fine.

7

Also it lacks a cam pin grove. Since the 9mm AR bolt (which is intergral with the carrier) does not have a cam pin. With that said you can use a regular 5.56 upper for the build without issue.