Without a cylinder guide sleeve, it’s very easy to push the bolt forward with the nozzle entering the chamber at a slight angle. It’s because you are left or right handed so naturally you are pulling or pushing in one direction more than the other. This can cause wear on the nozzle. But if it’s NOT that, and the bb stoppers are NOT too tight, I’ve had a certain nozzles fit tight into a certain bucking. Nozzle placement is one of the most important adjustments to improve accuracy. In my opinion, after messing with it. One way to do this is add a damper pad that’s 1-1.5mm thick on the back of the hop chamber, where the cylinder head hits. However, it will only benefit you if your nozzle placement was too far in. You’ll only know if you see an improvement. If you add the damper and there’s no change, AND you still have a good air seal, you’re still in good shape because your nozzle won’t go in mega far into the bucking, and possibly fix your “last 2mm it’s tight” issue.
…Hope any of that made sense