Hey gang,
Might pick up a Colt 6450 and convert it over to a standard A3 upper. Was curious if any of you guys have done 9mm builds on non-9mm upper receivers? I know the forward assist will not function, which is fine, but I was wondering what kind of ejection to expect with a standard 5.56 brass deflector...brass in my face or will it work?

I used a CMMG upper with the 9mm deflector.  Worked fine for me.  I removed the forward assist, and even with out a plug, there was no blow back debris.

Quoted: Hey gang, Might pick up a Colt 6450 and convert it over to a standard A3 upper. Was curious if any of you guys have done 9mm builds on non-9mm upper receivers? I know the forward assist will not function, which is fine, but I was wondering what kind of ejection to expect with a standard 5.56 brass deflector...brass in my face or will it work?

The 9mm deflector is for gas not brass you will be fine. Mike