I shoot the win 333's with out a single issue with my hunter. And at 20m I can make less than a 1 inch 10 shot group off a rest.
I do like it very much.So , I think you are really like this gun , yea ?
A rule of thumb is to use high energy 22s in semis. You can find this info on the pack. If not multiply velocity and projectile weight and youll get the momnum
Is CCI Stinger 22lr Varmint HP OK for this gun ?
Sure, I shoot Stingers out of my MKIII all the time.