I have been a 215 guy for many many years, but I have cut ES/SD numbers in half on a few rifles by switching to CCIs. I`m sure it has to do with the fact that I`m using a spherical powder in them. I still use mainly 215s though. I just feed my rifles what they like. Not sure if it really makes a difference, but it makes me feel better as far as consistency goes. I guess I could try switching back to 215s and take it out to a mile and see if I can still hit my gong Lol. Have plenty of 215, and 215Ms, but down to half a brick of 250s.