http://www.hodgdon.com/data/rifle/300winma.php

Why wouldn't they use magnum primers?

They are useing whats giving the most consistant results. I the use the fed 210 match primers in my .300 WM with excellent results
Wayles

Have you ever compared them with a chrono against magnum primers?

Hi
No I have not chronoed the 2 primers .I loaded Identical loads with fed 210 and 215 match primers and went with the more accurate. I wish I had ready access to a chronograph. One day I will invest in one .
Wayles

http://shootingchrony.com/products_SCMMCM.htm

Thanks for the reply.The link above has reconditioned ones for $50.Just scroll down to the bottom.Not a bad deal at all.

glockmeister,

I think you'll find it varies from rifle to rifle and from load combo to load combo. I've seen lowere spreads w/ 215GMMs vs LRs but, I've also seen it the other way around. I've generally had better luck w/ the 215s in mags.

Good Luck

Reloader

I'm moving more & more away from magnum primers. They seem to throw spikes in many loads & are not really needed unless you are shooting a large volumn of slow powder. Even in my 7mm Dakota, FED120M give better accuracy than 215mags.