Originally Posted By: bushycant find any cci 450's but I did pick up some 7 1/2 BR primers...looks like I'll be shooting them for a little while. never used rem primers before, should I expect anything different from the 450's?
I ended up in the same boat you are in. I found a thousand Rem 7 1/2 primers, and bought them so I'd have some primers to load with.
Over the last three weeks, I've been testing them. My go-to primers in the past have been Fed 205's and Winchester Small Rifle's.
Not all loads that I tested shot good, but I got a couple that will put the 7 1/2 in first place for accuracy, better than the primers I had been using.
I have the load test results down in my loading room and will have to go through it to find out specifically what loads shot great, and I'll pass that info on to you and others who have them and are looking for what works.
Keep in mind, just because they shot well in one of my rifles, doesn't mean they'll work in your rifle. But, my loads that do shoot would be a good starting point for you.
It will take me some time to go thru all of the targets, and I'll post about it later.
Also, back in the early 1970's when I was shooting Centerfire Benchrest competetively, all I used for primers was Rem 7 1/2's, and so did all of the other competitors. Then came along Federal, and the Federal's blew Rem primers out of the water. Don't recall what year that was, but I switched to Federals at that time and haven't used a Rem 7 1/2 since. One load that I remember shot well back then, and does so in my recent testing was for the 222 Rem. 19.5 grains of IMR-4198 and a good 50/52 grain bullet with the 7 1/2 sot extremely well, good enough to win matches back them, and still shoots today, with Berger 50 and 52 grain Varmint bullets.