Purpose-built for 9mm AR-15 pistol caliber carbines, our Generation 2 PCC blow-back carriers keep the features of our well-loved first BCG with modern improvements. We maintain the dual COLT/GLOCK compatible geometry, user-removable weight and full-auto compatibility while adding new and welcome features. We maintain a "ramped" bottom so any common trigger can be used - ideal for competitive shooters and plinkers alike.