I have killed deer with single bevels, double bevels, and 3 bladed heads. I honestly can't tell the difference. Some blood trails are awesome, some marginal. The biggest factor in my opinion is how much fat/tallow is lying under the hide. I shot a doe once up at Shrewhaven who had been feeding on acorns all fall....very fat. Double lung, perfect shot. She hardly bled until it started coming out of her nose. Autopsy showed that she had about 2 inches of tallow that closed up like ethafoam.