im shooting a TC Omega with CCI 209m primers and 100 grs of blackhorn 209 with 300 grain slick glide shockwaves. My barrel was spotless before i shot the other day and i cleaned out my breach plug like blackhorn told me to do wih the drill bit and it was spotless too. By all means im not complaining about this powder, i really do like it i kinda thought i was doing something wrong that iwas getting alot of blowback. To me it seems the CCI 209m primers are just really dirty.