MVB’s 45 ACP adaptor is designed as a drop-in accessory for a standard AR-15 lower receiver and uses a standard H&K USC 45 caliber magazine.
Has one set screw to tighten
Holds open on last round

Known compatibility issues:
**THIS ADAPTOR DOES NOT ACCEPT GLOCK MAGAZINES**
Will not work with the New Frontier Armory .45ACP bolt.

Does work with our URPBCG45G 45ACP bolt.