Sorry, I've been so many places trying to research potential Sniper XR purchase I'm not exactly sure where I read what. But poke through the various UK Air Gun forums.
In any case, from what I gathered, the gist of leak problem is longer term storage. And cocking level sounded like a tolerance issue, where it might be binding/rubbing the frame slot. First issue most likely requires factory/dealer service. Not sure if there would be User remedy for the second. Overall, might raise some concern for general QC..
Also, guessing that at this point of sales, that the sample size is fairly small and that Owners with problems tend to voice them more quickly than those with praise.
Bo3b