Do bench rest primers generally give you less velocity than standerd primers or are they the same? Is there a very large variation in velocities from brand to brand? I've been using bench rest primers in my 30.06 to try and shoot better groups.
With CCI and Federal they are identical strength to their counterparts. The Rem 7 1/2 BR primer is a magnum strength primer in comparison to the 6 1/2.
CCI and Federal claim their BR primers are more consistent across the measurable range. To date, the only misfire I've ever had was a CCI BR2 primer.
I think the best argument for using BR primers is the confidence they create - a perception. Otherwise, I'd bet it would take a very accurate rifle, superb optics and a fine shot to tell the difference between quality brand-name standard & BR primers.
I use Rem BR primers in my Rem 700 VS 223. Otherwise, it doesn't really matter to me - unless I'm experimenting. In a typical huntng rifle, I haven't seen any evidence that suggests the choice of standard or BR primers makes any real difference in accuracy.
It might make a difference in extreme long range shooting where a slight improvement in SD makes a measurable difference, but in a hunting rifle....