There is nothing more crucial to the performance of your AR-9 than the bolt carrier group. Made to MIL-SPEC and finished with superior quality nitride finish that protects against corrosion and heat, our BCG wont let you down. In order to ensure that it will run beautifully in your AR-9, each bolt carrier group under goes high pressure testing (HPT), and magnetic particle inspection (MPI). Whether you are looking for a drop-in Mil-Spec quality replacement for your current AR or are going for a new build, this bolt carrier group provides you with the reliability and performance you expect from a first-rate product.