The jackhammers are a strong well made head. The fly great and the blades are sharp. The only damage they recieved in my steel drum was on blade tip bent, but the head penetrated very well. The open a little slower than many of the heads I have tested, a little faster than the spitfires, but slower than the the rocky snypers. I think they are a very good mechanical head.

TAKE YOUR KIDS HUNTING AND YOU WON'T BE HUNTING FOR YOUR KIDS