i think its cause the 2 blade leaves a slit, rather than an X if you will..i think a slit closes up easier. i use the snuffers..3 blade 125's, only had one time when i hit her high, it took 50 yards fer blood to come out, but it was pourin and she only made it 20 more yards... never had a lack of blood other than that....since i started with the snuffers