They say the Trifecta flash hider isn't supposed to ring, even though it is open on the end. I still wish it was closed, just so it wouldn't catch grass and foliage so easily. Same reason the .mil went to the birdcage over the duckbill flash hider when the M-16A1 came out. I suppose I'll still use them on most of my rifles. I have an Omega on the way, and I don't like brakes.