I've been a Crosman 2300S owner for a couple of weeks and this is my first co2 gun and I'm in the process of learning. Today I cleaned and oiled my pistol after shooting 100 rounds on Thursday, I was just plinking to get familiar with the gun. So far I've learned that my gun doesn't like Daisy pointed pellets and RWS Diabolo Basic wadcutters, these pellets will not go into the barrel without forcing them and the deform easily while loading. I also tried Crosman Premier Pointed pellets and these load easily into the gun. Next week I'm going to try Crosman Premier Piranha which seem to load easily too. My first mistake was with my first co2, I couldn't get it in far enough using my fingers so I used a quarter and may have over tightened the end cap because it was so tight I had to use pliers to get it off. Today I loaded a co2 but didn't plan to pierce it. I sanded a burr off of the threads of the end cap and the end cap screws in easily now. I didn't think the co2 was pierced and I unscrew the end cap to remove the co2 and the co2 went off, I'm hoping I didn't damage the gun. I'm also having a problem with the Williams sights, they are mounted to the gun but canted to the right a few degrees, I've removed and reattached the sights several times and I cannot get them on straight. Next week I want to dial the gun in at 10 meters and hoping I can figure out how to get them on straight. I'd greatly appreciate your comments.