Old Syko,
Yea, I'll too will never understand why barrels of the same chambering, same length, same material and same manufacturer perfer different components. It's wierd. PJ's old 7-30 barrel, for example, prefered IMR4064 and didn't like W748 which mine loves. I too haven't had much luck with Winchester primers but there sure are enough folks out there that love them.
Thanks for the comments about the CCI250s. It will encourage me to keep trying them. In fact, I haven't tried them with IMR 4064 so maybe they will be the ticket. I really like the increased velocity 4064 offers over W748.
Merry Christmas!
ShootnStr8