I just hit a big sow yesterday and thought it was a perfect shot from about 20 yards, tracked her for 2 hours and finally lost the blood trail. After inspecting my arrow that was broken, I realized that I only got about 9 inches of penetration. I was using a 200 grain stos, 2213 aluminum..total arrow weight of 550 grains, out of a 55 pound recurve that shoots hard. I couldn't believe it. Very disappointed. My broadhead was sharp but not razor sharp. I can get them to cut hair but not "pop" hair like I want. I don't know if that was the problem, but regardless, I will be trying 3 blades to see if I can sharpen them easier or I will be investing in a KME.