Based on my limited experience with them (this year), shooting a 290 TMZ over 100 gr of T7 pellets, I can confidently say I dunno! First shot was in the intestines, hair at the sight of the hit- no blood. Deer ran approx 50 yards and bedded within sight. As I approached it, it got up and went a little ways on wobbly legs. Second shot, right behind the front leg and profuse bloodtrail. Upon further inspection, exit in the front shoulder and bullet went on ( so did the first). The fact that I got exit wounds was a plus, since most I have not with the mz. The first shot being sent off course by brush and into a non vital area I would not expect much blood (some maybe?). The second, could not ask for better results. I will definitely give them another go round, but at the suggestion of Doohan will also give the Parker BEs a try.