A friend gave me a significant number (5000ish) CCI SP 550 primers. I do shoot some .38/.357, but not to the point of loading it yet (soon).

I mostly load .45 (using LP primers, of course) and 9mm and .380.

Is it safe to use the SP 550 (magnum) primer in 9mm and .380 loads?

If so, does it alter the safe powder loads?

not recomended to use magnum primers in 9mm or 38spl loads, can lead to pressure problems and can negatively affect accuracy. rather use them in 357mag loads where larger loads of slower burning powders are used. good luck

quote:

Originally posted by blacksmoke:
not recomended to use magnum primers in 9mm or 38spl loads, can lead to pressure problems and can negatively affect accuracy. rather use them in 357mag loads where larger loads of slower burning powders are used. good luck

I agree with the accuracy part, but you can certainly load magnum primers safely in 9mm & 380. Reduce your loads 5% & work back up.

I contacted RCBS (CCI) about that very issue and they said it would be fine if you backed off your powder a grain or so.

Thanks for the input. That was what I was hoping for. I've loaded some .380s with it (only 30 rounds to test this weekend) and did load them light.