Purchased a Chaser "kit" in .22 cal recently, and had some initial problems with the pistol barrel. It seems it would not load pellets smoothly, requiring some care/finnigling while pushing the bolt home to chamber the pellet. Decided to inspect the barrel a bit closer, and noted some burrs and less than ideal machining. I decided to clean up and "smooth" the chamber entry just a bit using a Cratex abrasive cone, made a big difference in how the pellets chambered, nice and smooth now. I also picked up a spare Diana moderator for the barrel, and decided to machine off the sight blade prior to installing the moderator. I think it looks much nicer now. I was not going to use the open sights anyway, so no harm no foul