I think that you need to understand a couple of things to get a handle on this. First of all some very good shooters believe that tune in velocity specific. That is why most published primer comparisons are deeply flawed, they hold powder charge constant (as well as everything else except the primer) but since primers differ in how hot they are, and the velocities that they produce in otherwise identical loads, the tests end up producing results that may be misleading. IMO what they should do is adjust their powder charges so that they all produce the same proven (for that rifle and bullet)veolcity. Having said that, it is generally a pretty well established principle that for a case of the size of a .222, the coolest primer will produce the best results for match work. That would leave you with the Russian magnum small rifle primers, that have the same pellet size as the regular Russian small rifle primers but with a tougher primer cup. Slightly hotter than that, the CCI4 and Federal 205 or 205M of which I have never been able to see a difference on the target. From there, the Winchesters are a little hotter, and the Remington 7 1/2s the hottest. For field work, I think that I could work up perfectly satisfactory loads with any of them, and unless you are shooting off of a good bench, with a reasonably light trigger, good rest, and bags, and are using wind flags of some sort, you will likely be wasting some effort worrying about which primer, as long as you remember to tune up your load for a specific primer, and not try to apply the load that worked well for one with another that is a lot different. Having said all of that, most of my bench work has been with Federal primers, Lapua brass, and 53 grain sierras seated about .006 longer than touching, at a velocity around 3,250 from a .22" barrel. Now go have some fun. BTW working up loads at the range is so much better than anything else. If you don't already, I recommend that you give it a try, and not with the old five of these and five of those approach, that is such a waste of time and money.
I know every gun is different, but I wanted y'all's opinion if it was worth paying a lil extra for the magnum primers or the BR4?
