Cant go wrong with this set up - Rosco Manufacturing K9 AR-15 Sauce Pack 5.56mm Threaded Rifle Barrel

I run this 12.5” barrel suppressed all the time and it runs like a charm because of the patrol length gas system. It is softer shooting than a carbine length gas system but has enough dwell time to run consistently unlike a 12.5” mid-length. Additionally the ballistics are extremely similar to a 14.5” mid-length especially within 400 yards. I absolutely love the 12.5” patrol system, I have two of them.