I want to substitute Winchester WLRM primers in place of Federal 215. My load is 82.4 gr of H4831sc in a 300 win mag with a 125gr nosler ballistic tip. I was goin to start about 5% lower that my normal loads to see if there is pressure issues. Or should I use the Federal 210GM I have?

With the reduction you had in mind, a substitution should be no trouble. Heck, I only drop about 3.0 grains when I change primers, but I'll drop even more if it's a max load.

ok thanks for the info I just wanted to be sure If i could do that. On my way to the bench now
I will try the WLRM thanks