Magnum primers substitution

[bsterns]

What would be the results of substituting magnum primers for large rifle primers? Is there any instance where this would be okay or preferred. If so then in which case would you do that? Thanks

[L. Cooper]

The result will be changes in pressure. Most likely, but not certainly, there would be a higher peak pressure.

The only safe way to substitute ANY new component into a load is to start with a low pressure load and work up to toward maximum.

Some people believe that magnum primers are better for loads that will be used in extreme cold. Only testing will prove anything for your specific loads (which you don't describe at all). I use the same magnum primers with any data for any cartridge from any manual that used magnum primers in their tests to arrive at that data.

[Catfish]

Large rifle primers are usuall prefered in large volume cases. They can be used in more what I will call normal size cases, but you will need to drop you load by at least 5% and work up again to be safe and you will not use quite as much powder unless you load was under max. Accuracy may also suffer with mag. primers, but not always. With small cases mag. primers can blow the bullet out of the case befor it ignites the powder which can be dangerious and will always give you inaccurate loads.

[Catfish]

Seem like I`ve always been one to buy more componints than I can get shot up befor I move on to something esle. I about always get around to useing them up but sometimes it takes years. But now as I look at the stock pile I have I no longer ask myself why I got so much, I just smile and think how much more it`s worth now than when I bought it.