Guys, does this sound right. I found a nice little load for my 300RUM with 94g of H1000 CCI 210 Magnum primer and 180g of Nosler PT. Gave me consistent 3/4" accuracy at 100 yards. Well, by consistent, I tryed it twice and it worked. Well, I have never used those expensive fed 215M matchgrade primers, so I wanted to see if they would be better.

Well, at 94g of H1000, groups were 1.8". The best I could find was 92.5g and stil couldn't get those cloverleave groups. They were about 1" with a few at .9" or so. Are 215's that much hotter. I didn't chrono, so couldn't tell you the velocity differnce. Back to the reloading bench with CCI's. Have any of you guys, seen this much difference with different primers?

There was a post here earlier about this. Apparently, there are very big differences between primers. They don't make much difference in muzzle velocity, but they make a big difference in peak pressure, and that would probably translate to accuracy differences.

According to the chart, though, the 215 and 210 are pretty close. The CCI 200's produced much lower pressure in a 30-06 test.

bigcountry,
I have seen a change in primers that increased group size an inch and more at 100 yards. It it one of the last variables that I look at when working up a new load.

PaulS

Guys, I have seen somewhere a general rule that you might need to drop a certain grainage when changing from one primer (can't remember) to Fed 215M. Have any of you guys seen this?

What is the main reason for 215M's and where would there uses be the best? I went and shot a few groups this morning with the CCI's and I am back to my clover leafs, thank goodness.