I've only ran one test loading with different primers. It was interesting.

6mm Rem. Ran H4831 charges with 4 different primers. CCI 200, CCI 250, Fed 210, and Fed 210M.

Was surprised the Fed 210 and Fed 210M varied as much from each other. 200 fps slower, and a bit higher extreme spread. That was it for the Fed210.

CCI 200 was just worse than the Fed 210 in every way. If this test is any indication, I have no idea what I'll ever do with the 1000 CCI 200's on my shelf. A bit slower than the lagging Fed 210, really bad ES. Measuring cases indicated even at the slower fps, the case was showing similar pressure to the Fed 210M.

CCI 250 was really as much encouraging as the CCI 200 was disappointing. By far had the lowest extreme spread. But velocity was a little lower than the competitive Fed 210M.

I tested the CCI 250 - a large rifle Magnum Primer once before against a Large Rifle primer. Interesting thing is - the 250 was slower on that comparison too, not by much, but it was slower than the Large Rifle primer I was comparing to.. But the consistent velocities is where the CCI250 really shined that time too.

I ended up going with the Fed 210M with my 6mm, but I could have selected the CCI 250. CCI 250 actually did nudge it out by just a little - it's just that I have a few thousand more Fed 210 M primers than I have CCI 250 primers.

For me, on one intentional test, on this one gun of mine, with varied loads. It's CCI 250 first choice followed closely by Fed 210 M - toss up choice. Fed 210 is a reasonable and acceptable option - if never tested side by side to anything I'm sure you'd never be disappointed with Fed 210 performance.

The CCI 200 had no business at all in final load inclusion. It was comparatively bad in every way. Didn't expect that. Slow, with wide ES, and on top of that seemed pressure was higher at the slow velocity.

I'll test primers again on another load development. Didn't expect such drastic difference. And I'll be including a larger number of primer brands and models in my testing, load development. I was surprised the results were so drastically different.

Last edited by Burr; 12/04/18.