You didn't say how long you have had the rifle if it is new then I may be able to help u . I purchased a new one a few years ago and it did the same thing tried about every brand in it I could it would shoo cci stingers almost every time , anything else maby 3 or 4 out of ten. I accidently stumbled on the problem while reassembling one day, noticed the case rim didn't seat fully against the bolt face, was looking from the magazine well with the mag removed, I tried some different ammo and then stingers . T he stingers fit against the face of the bolt tighter , so I measured the rim thickness and they are a little thicker, I solved the problem by carefully filing the raised part of the bolt that fits over the rim a little at a time and reassembling till it would shoot anything I put in it . Then the only problem was it was never accurate enough so I traded it for a bolt gun. If your rifle is new ,check it , if it's an older one this probably is not the problem