Primers is it safe?

[K-C]

I use mag primers with all ball powders...so I use em in 222,223,7.62x39,30-30,308,30'06,8x57 and probably others I'm forgetting....
Work up a load, don't sweat the little things.

I agree, always use magnum primers for ball powder as it's more difficult to ignite...

 

[kayaker1]

Yes, work up the load as usual.

Be aware that some brands of regular LR primer can be as hot or hotter than other brands of LR magnum primer - there is no standard or baseline for measuring when an LR passes a threshold to become an LRM.
For interest sake the CCI350 primer (large PISTOL magnum) is one of the hottest/most powerful primers according to Mick McPhee's publication of lab tests.