CMMG Resolute Mk4 300 AAC Blackout 16.1" Upper Group

.300 BLK was developed for subsonic and suppressed use but now works well with both subsonic and supersonic loads. It suits hunting, home defense and target shooting. This upper completes a carbine build and comes with a bolt carrier group and ambidextrous charging handle. Lifetime Quality Guarantee covers material and workmanship defects.