They're pretty awesome ! I was given a really nice Steyr Model L .6mm by my father in law ...........and man..........it's a deer slayer ! It has dropped virtually every deer I have shot instantly ! I guess like a lot of guys said it's shot placement.............because I have tracked many of deer shot with 300 mags , 7 mags , 30-06's , etc. shot in the liver , heart, lungs , etc. for a long ways !! I shoot them in the shoulder and they drop like lightning hit 'em ..............even with a little ole .6mm !