I have not used them in a centerfire yet, other than paper punching with my .270. I did, however shoottwo does in the last two years with them in my muzzleloader. Don't aim for bone. The first doe I shot with one, was quartering away at about sixty yards. The 300 grain SST went through the left side about half way back on the ribs, there was no exit, and I had to disgard the whole right side shoulder. I have never seen one bullet do so much damage. The positive side is, she went pretty much no where after the hit. I shot a doe last year with the same bullet a direct broadside heart shot at about seventy or so yards. She took about ten steps and fell over. That one was a complete pass through and the exit was in impressive. They definately kill.