There is a graph on arfcom that compares bullet drop and velocity of various calibers (.223, 6.8 SPC, 7.62x39 and 7.62x51 were all included IIRC) which I'm pretty sure is somewhere in the ammo forum. I've seen this graph before here, but I can't find it. Does anyone know what I'm talking about? Can you post a link for me please?