reduction for magnum primers

[rw496]

I am loading IMR 4320 in 30-06. I have Remington 9 1/2 magnum primers, because that's all I could find around here and I have 1000 of them. The book says 41.0 - 46.3 using LR primers. I loaded 10 rounds from 41.0 to 44.5 in 0.5 increments. Does this seem like a safe enough reduction in powder? What is the minimum powder reduction when replacing LR with magnum in rifle cases?

 

[BobinNC]

When working up a load with magnum primers I don't do anything different nor do I make any reductions in starting or ending loads. I just load normally, work up the load and look for pressure signs.

This is especially true of 30-06 loads, which for the most part the loading manuals grossly under load because of numerous weak actions once made in that caliber. If you have a strong modern bolt action rifle of recent vintage you can work up 30-06 loads to well over book max. Most book loads for the 30-06 are capped at 58k PSI (60K SAAMI MAX PSI), but the 30-06 case is constructed identically to the 270 Win case, that has a SAAMI max PSI of 65K.

At one time years ago I used nothing but CCI 250 primers, as I had more rifles in magnum calibers than standard ones, and never noticed any remarkable differences in my loads. Even today, I stock only CCI 450's for those cases that take SR primers. Though that is more a function of primer thickness, as I make more loads for an AR15 than I do for SR bolt guns.

But I am curious as to what bullet your contemplating loading in your 30-06, as Hodgdon Reloading does not use the powder for bullets over 180 grains, and the smallest starting load they list for it is 45 grains of IMR4320.....

 

[rw496]

When working up a load with magnum primers I don't do anything different nor do I make any reductions in starting or ending loads. I just load normally, work up the load and look for pressure signs.

This is especially true of 30-06 loads, which for the most part the loading manuals grossly under load because of numerous weak actions once made in that caliber. If you have a strong modern bolt action rifle of recent vintage you can work up 30-06 loads to well over book max. Most book loads for the 30-06 are capped at 58k PSI (60K SAAMI MAX PSI), but the 30-06 case is constructed identically to the 270 Win case, that has a SAAMI max PSI of 65K.

At one time years ago I used nothing but CCI 250 primers, as I had more rifles in magnum calibers than standard ones, and never noticed any remarkable differences in my loads. Even today, I stock only CCI 450's for those cases that take SR primers. Though that is more a function of primer thickness, as I make more loads for an AR15 than I do for SR bolt guns.

But I am curious as to what bullet your contemplating loading in your 30-06, as Hodgdon Reloading does not use the powder for bullets over 180 grains, and the smallest starting load they list for it is 45 grains of IMR4320.....

Thanks for the detailed reply. For now I am loading Hornady 180 gr BTSP and using the Lyman manual.

 

[BobinNC]

IMR Load data for the 30-06 and IMR4320:

180 GR. SIE SPBT IMR IMR 4320 .308" 3.300" 45.0 2525 49,900 PSI 47.8 2661 58,000 PSI <tbody> </tbody>

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Here is interesting test of primers in a 30-06 you might find useful. http://riflemansjournal.blogspot.com/2009/06/primers-large-rifle-primer-study.html