ihmsa forums

I picked up 1000 small rifle magnum primers. Has anyone used them in 7br or 6br loads? I have read that CCI 41 primers are basically sr magnum primers with a harder cup? Has anyone used them in the br cartridges?

In a search of various websites, the consensus is that regular versus benchrest versus magnum offer little difference.

There are many threads about this identical topic.

If you have access to a chronograph, i would test 5 with your regular load and your normal primer compared to these magnums.

One thread i read said that the difference is less than 5%. If you’re running 2000 or less out of a pistol thats probably way less than 100fps.

I would test in your gun because in my experience, when it comes to reloading, everything is a variable and affects the outcome.

I ran a test using my 6.5br. The magnum primers were 50-60 fps faster. BUT, in my gun, the firing pin spring is a bit weak, and there seemed to be a lag between the trigger pull and ignition. The gun would go bang fairly promptly, but the mag primers seemed a little harder and ignition didn't seem to be as fast. And that appeared to have a detriment on accuracy as the firing pin moved but ignition was slower. I'll do more testing after the IHMSA Championships.
Your mileage may vary.