I’m looking for insights and recommendations on 9 mm uppers. The ones I’ve seen for sale are the Rock River Arms (RRA) midlength (MID) and carbine length (CAR) uppers, and the CMMG carbine length upper.
I know the CMMG comes with a ramped bolt that works with standard AR triggers. The RRA requires a 9 mm trigger, unless you get aftermarket machining done to ramp the bolt. I’d like to install the RRA two stage trigger, so if I get the RRA upper, I’ll get the bolt ramped. Can anybody share thoughts and experiences with a ramped RRA 9 mm upper?
The CMMG upper has the standard AR forward assist and brass deflector. Is the forward assist actually functional on a 9 mm AR upper? Has anybody ever had to use it?
Finally, I’m interested in the weight differences. Does anybody know the weights of the CMMG upper, the RRA CAR upper, and the RRA MID upper?
Any other insights also appreciated.