Switched to mechanicals (spitfire 100s) last year. Two of my buddies started shooting the same heads this year after my sucess last year. Between the three of us, we shot 13 deer this year, at different angles from 6 to 28 yds. All deer dropped in sight, except for one which was a bad shot, hit in the neck and missed the artery, but still dropped after 60 yds. Several of the deer were not hit "perfact", but from the size of the hole and amount of blood loss, luckily not a problem. The guy at my local archery shop suggests these heads to customers, and I've never heard anyone complain of their performance on deer. Just know your effective range and don't take low percentage shots.