Magnum primers

[dbaird]

Can you use magnum primers to reload .243/.308/.30-06?

 

[358WCF]

Yes. As with any component change, reduce the load a bit & work upward.

 

[Loudenboomer]

Most would say Magnum primers would be the preferred choice with Ball powders.

 

[MGYSGT]

All I use. Started using them during the primer shortage of Obama years. Never switched back.

 

[RegionRat]

Most would say Magnum primers would be the preferred choice with Ball powders.

+1

If you put the work into a ball powder load development, you might as well start with a magnum primer so that if and when you take that load into cold weather you don't have to do it all over again.

One of the confusing things about primers is the difference in pressure ratings versus brisance.

The pressure capability of the actual cup metal and strength affects your choices when it comes to rifles that operate well above the old pistol pressures or have to have safety margins against slam fires.

The brisance is what affects the powder combustion. You end up needing to do your homework to find out what primers you like, but since typical rifles can use regular or magnum primers it boils down to doing your homework and load development to see what works for you.

In otherwise typical settings of regular rifle loadings, the magnums can be substituted with a load work up to make sure you don't go out of tune. Just as often it works out very close or requires a charge adjustment.

Since you are asking a background question, I will just caution that some primers don't take rifle pressure, and some are low margin against slam fires.

Try and stick with load manual recipes if you are a beginner, but if you are ready to substitute for example a CCI400 with a CCI450, then you would want to budget for a test where you take the "old" charge of the 400 down about 2% and let that tell you if the load responds well to going right back to the previous value or needs a tweak.

The closer your "old" load is to being hot, the more careful you should be about dropping the pressure before you test anything new in the recipe. If you don't understand internal ballistics and safety margins, it is best to get a mentor or stick with published manuals. Play it safe and good luck.