I can truly say that you will be absolutely amazed at the difference that Bobs trigger will make. As for what kind of accuracy you can get out of an airgun,,,, it of course depends on quite a few factors as you are well aware, however that being said I can honestly say that all my airguns are used for hunting and they all provide the accuracy I need for accurate hunting shot placement. Some guns of course give much tighter groups than others but my "worst" guns give me quarter sized groups at 30 to 40 yards. My "best" gun will give me one ragged hole groups or close to it at the same distance. As for 50 yards,,, I don't really shoot at 50 yards, my self imposed limit for hunting is usually 40 yards or less. I have shot further on occassion, but for the most part I try to stay 40 yards and under, and in actuality most of my hunting shots are probable 30 yards of less.. Some of the other members may routinely target shoot at 50 plus, they would be better qualified to speak about accuracy at those distances.....
That's one of the things I really like about air guns,,, the challenge of shooting them well. I'm sure you will have no problem attaining the accuracy level you are looking for once you install Bobs trigger and practice with your Big Cat.
Jeff