Question on primers for ya. I am loading my 445 supermag with federal 155 match primers and my load is close to max but not there yet but my primers seem flat to me. I was wondering if they are softer than standard and will flatten easier?

Also the book states federal 210 for the max load. So wonder if they are harder and wouldn't show the flatness that I am seeing with the match 155 federals?

Thanks

Brian

Federal 210's are rifle primers. Their match grade version is 210M. Aren't you using a pistol primer? Their cups are softer.

Bob257

Match primers are intended to be the same as their regular counterpart, just better tolerances and consistency. If your load data calls for #210 and not #155, you could expect that the pistol primer would deform before the rifle series as the cup is thinner material, not necessarily softer (within the same brand).

Thanks guys for the info, I was thinking that was the reason but wanted to make sure.

Brian

Most of the Supermag line of cartridges operate at rifle pressures or near to it. I think your problem will go away if you switch to the rifle primers.

bowhuntr