I've been reading several posts about the problem of chambering the pellet when the loading block goes over too far and misaligns with the chamber. It's really easy to fix, either permanently with a small dab of epoxy, or semi-permanently with a small piece of duct tape. For the quick 'n easy fix, just cut a very small strip of duct tape and stick it to top part of the loading block lever where it contacts the action when rotated into loading position. The dimension of that tape seems to be just right to align the block with the chamber mouth.
Just pull the lever straight out (don't lose the little leaf-spring) and you can work on it easily. Same thing goes for using the epoxy. Just put a very small dab on the same area of the lever, let it set for a while and then rotate it until the chamber is lined up. Back it off and let it set some more, then try it to see if the alignment is still set. It not, do what's necessary to align it and then let it cure.
The 'really' easy way, of course, is to just reverse the lever and see if that does it. Often times, it does. Feelin' Lucky??
Bob