Converts the Cavalry Arms and GWACS MKII plastic receiver to accept AR 9mm magazines.
Adapter drops into the top of the receiver and impossible to remove unless the upper receiver is opened. Special 9mm bolt catch can be used for last round hold open.
AR 9mm Magazine
FOR COLT/RRA STYLE 9MM UPPER RECEIVERS ONLY
WILL NOT WORK WITH STANDARD ALUMINUM LOWER RECEIVERS