Primers

[Don McDowell]

In this regard I'm of the firm belief that a rifles choice in primers is the only thing exactly like smokeless. Some rifles like this primer some don't, once in a great while a rifle just isn't picky. Some lots of powder resond well to primer A the next lot might be absolutely repulsed by that primer.
I will say that across the board I generally start initial load work up with either the RP 91/2 or BR2 and then when tweaking loads wander off into the primer box.