Let’s fast forward some years later. The first carbine I put together was, you guessed it, a 9mm AR. This was a more contemporary semi-auto interpretation. It featured a 16″ Rock River Arms Upper Receiver on a CMMG Lower. Because I live in the People’s Republic of California and a SMG, SBR or pistol were all out of the question. While one of those would’ve been cool, a 9mm bullet out of a carbine-length barrel is ballistically comparable to a .357 magnum. I chose the RRA upper over the CMMG because I’m particular, I didn’t want the forward assist on CMMG and liked that the RRA resembled the Colt. So I took the upper half to local shop, Addax Tactical, had them knock off the A2 and install an A.R.M.S. #41 Folding Front Sight Post then chop, crown and thread the barrel at 14.5″ and pin a Smith Enterprise Vortex flash hider. I also exchanged the RRA BCG with ADCO Firearms for a ramped CMMG Enhanced Bolt Carrier. I replaced the RRA charging handle with a PRI 9mm Gas Buster. At the time, most 9mm lowers, including the Colt and RRA, were mil-spec forged 5.56 lowers with a magazine block inserted into the magwell enabling it to accept the Uzi mags. These mag blocks were known to be somewhat problematic which was why I went with a CMMG MK9 Dedicated Receiver. This forged receiver’s magwell is machined to accept Colt pattern mags without the use of a block. From Spike’s Tactical, I installed a Battle Trigger (NiB) with JP Rifles Reduced Power Spring Set, ST-T2 (Buffer) and ST-9BS (buffer spacer). The trigger was held in by KNS Precision Anti-Rotation Pins. From Magpul, I added their ASAP (brand new at the time), MOE furniture in Foliage (hot at the time) and eventually a SSG which was a bitch to fit. Last, I sighted in a Burris FastFire 2 (not pictured), mounted on a AR-F3, at 7 yards.
