Re: Primer for lowest ES
Ive got great results from Federal primers, and CCIBR2, and RWS... I think that there is a bit of magic to the mix in terms of a particular powder liking one primer over another. Don't get me wrong, there are definately good and bad lots in all makes and models, but I think that powder compatability as more to do with it than anything else.
For selecting primers for LR use, I typically get a couple of different lot#s of a given primer that I know performs well with the powder, then seat them in FL sized 308win brass necked down to 243 without an expander ball. I seat one of the heavier 6mm plastic bbs into the case (12gram... 14gram... I forget which), then shoot it across the chrony. This will give you a comparison as to which lot is most or least mild, as well as the most consistant. I will often buy 100 of a given lot, burn 20 primers in testing, shoot a ladder to find the load, then go back and buy however many I think im going to need for the given load, or to layback stocks for the forseeable future. That way I know im using a primer than has a known level of performance and consistancy.