I've just been trying out some of the 200 grain Shockwaves out of my Black Diamond XR. Accuracy wise, they are fantastic. I shot them with 110 grains of loose T-7 and all three holes touched at 100 yards. I think a quarter would have covered the shots.. As for knock down, I do not see why they would not be effective. I mean people are shooting smaller projectiles then that at deer and taking them at some extreme distances...