9mm Tech

9mm Configuration Overview

For General Tech details see 5.56 Tech. 9mm Configuration specifics are covered below. Every 9mm blowback setup differs, and upper brand compatibility depends on adherence to Colt upper specifications, which most AR uppers follow.

Fire Rate

9mm approx 1100 rpm.

Arizona Regulator Test Setup (16" Carbine)

Standard 5.56 A2 rifle lower. 16" Colt 9mm upper. Foxtrot Mike Colt style mag BCG (part # FMC-9BCG). Kaw Valley Precision 10 oz tungsten carbine buffer (part # KVP-10oz). Kaw Valley Precision XP carbine buffer spring (part # KVP-PCC-XP-Spring). Mean Arms Endomag 9mm mag conversion kit with built-in ejector in PMAG 30 (part # MAG557-MCT). Spacer configuration for proper bolt catch operation.

Short Barrel Pistol Configuration (7.5")

Yankee Hill Machine 9mm Upper. Foxtrot Mike Colt Mags 9mm BCG. Kaw Valley Precision 10 oz tungsten carbine buffer. Standard carbine buffer tube. Standard carbine buffer spring. Bowers CAC9 Suppressor.

Critical BCG Warning

Ensure whichever std FA compatible BCG you use does not have an additional pinned in weight in the tail of it that extends forward past the trip release surface. Notably the Colt pinned in weight does exceed forward of the trip surface. The pinned weight interference prevents receiver closure. Solutions include relieving material or using Foxtrot Mike BCG with compatible weight configuration.

Buffer Requirement (Mandatory)

YOU MUST USE A 10.00 OZ BUFFER WITH 9MM AS THOSE ARE THE PROPER LENGTH TO ENSURE THE ORIGINAL COLT TIMING FOR THE 9MM COLT MIL-SPEC GUNS IN MAINTAINED. The 10 oz buffer matches original Colt 2-piece 9mm SMG buffer specifications.

Troubleshooting

Non-MIL-spec parts may cause self-induced issues. Users should verify buffer tube compliance (original Colt rifle and carbine tubes are industry standard). Recommend consulting local gunsmith if issues occur after following instructions.