Good deal Smurf! I got a new rear sight for my old Makarov - found a place that makes a drop-in replacement for the klunky oem sight. And my Sweetie got a red/green sight for her AR. And we both got some new NRA shirts. :thumb:
Yeah, I think everyone breaks those. You can order a few from Umarex. I took my flash hider, and made the o-ring slot a bit bigger/deeper, (I have a lathe) and then used a larger o-ring. Have never had another issue there. The o-ring is important for accuracy. As you have noticed by now, the actual barrel is tensioned by tightening the flash hider. The o-ring centers the barrel and is needed for accuracy. I also put small registration marks on the flash hider and barrel shroud so that I get it to the same tension every time. TM