CCI Magnum SRP

[vossman]

Had a friend give me a few hundred of these. From what I understand, magnum primers are harder rather than more powerful. Can I just substitute these or do I need to work up a load again. Not looking for any accuracy, just plinking. .223 current load is a Rem BR primer (#7 1/2 I think), 24gns of H335 under a 55gn FMJ which is nowhere near max and shows no signs of pressure.

[Jamnanc]

Meh load em.

[Great-Kazoo]

Try 23gr as a starting weight. When I've used MPP, or MRP, I'll start 1gr low across the board..

[Zombie Steve]

Back off a little and work back up. I've had these primers make no difference on light loads, and equate to a half grain or more difference in warmer loads.

[vossman]

Thx