First time out with my then new sbe 3 at the clays range it fell off the golf cart at full speed onto the sharp gravel road and got some nice deep gouges. Nothing to be done and it still works fine so it doesnt really matter.
I had my m4 entry threaded for chokes by briley so its the same pattern as my full size m4 not rem chokes. I did it because I wanted to be able mount my salvo. I think it was a $150 and I have absolutley no regrets.