Description
- Fully ambidextrous 9mm AR-15
- Forged 7075-T6 receiver set
- Colt magazine pattern lower accepts Colt or Metal Form 10/20/32-round magazines
- 1/4-28 nylon-tipped tension screw for tight, adjustable lower fit
- Magazine well natively sized for Colt 9mm magazine
- Proprietary 17-4 nitrided feed ramp tuned to center cartridges
- Feed ramp secured by three allen screws with whistle-notch interface
- Combined ejector and bolt catch extension in one component
- Brass buffer in receiver extension approximates M1A1 Thompson weight
- Buffer limits BCG travel to prevent casing jams
The Griffin MK2 9mm is a fully ambidextrous 9mm AR-15, and is the first full-ambi 9mm AR-15s with a forged 7075-T6 receiver set. It is a Colt magazine pattern lower capable of receiving Colt or Metal Form 10,20, and 32 round magazines that have the classic Colt SMG look. It has a 1/4-28 Nylon tipped tension screw equipped lower for a tight fit that can be adjusted to fit end user's preferences.
The feed ramp and magazine interface in this system was improved over Colt. Rather than use a magazine well adaptor assembled to a 5.56mm lower with roll pins to remove excess volume of 5.56mm lowers, the magazine well was natively sized for the Colt 9mm magazine. The proprietary feed ramp was tuned to deliver cartridges perfectly to the centerline of the chamber of the barrel, unlike the original, pre Colt design which may not have involved a capable CAD system. The ramp is affixed solidly by three allen screws which pull the 17-4 nitrided feed ramp down into the receiver very aggressively utilizing a whistle notch type interface adapted from the CNC cutting tool industry for rock solid interfacing of the feed ramp. The ejector was combined with the bolt catch extension in one component that is intended to work properly as they are put together, needing no "adjustment of the ejector" as with the original Colt system.
The buffer in the receiver extension is brass for increased weight to approximate the weight of the M1A1 Thompson operating system to drop rate of fire and is sized to limit the travel of the BCG so that casings cannot become lodged in the fire control pocket. These 9mm guns come equipped with Griffin's adjustable 2-stage triggers, which are configured at the factory for functional use right out of the box. This Griffin Armament match trigger is a Kreiger Milazzo style two stage trigger, combining a mil-spec 62RC 8620 trigger material and heat treatment regime with a 53RC 440C tool stainless disconnector, and 440C nickel teflon coated tool steel lightened speed hammer. The factory pre-adjusted triggers feature adjustable overtravel and adjustable disconnector engagement, allowing end users to get the refined feel that they want if the standard adjustment isn't quite perfectly suited to their taste.
The barrels are headspaced .01" short to reduce the sound of bolt slap when used in conjunction with a sound suppressor, and the SR handguards allow interfacing of cans up to ~1.550" diameter (although suppressor overlapped M-LOK slots may be unuseable).
