Every reload manual and Loading Data I ever looked at never mentioned Magnum Primers at all. Not even for Magnum cartridges...Magnum primers are used mainly to ignite slower, hard to ignite, powders.
Just follow the data you use.
It'll say if they used Magnum primers or not.
Powders from Hodgdon will use them when the cartridge name includes the word "Magnum".
Like .32 H&R Magnum, .327 Federal Magnum, .357 Magnum, 41 Magnum, 44 Magnum etc, etc.
Every reload manual and Loading Data I ever looked at never mentioned Magnum Primers at all. Not even for Magnum cartridges...
Every reload manual and Loading Data I ever looked at never mentioned Magnum Primers at all.
Every reload manual and Loading Data I ever looked at never mentioned Magnum Primers at all. Not even for Magnum cartridges...
Every reload manual and Loading Data I ever looked at never mentioned Magnum Primers at all. Not even for Magnum cartridges...
The best answer is testing all options in your shooting environment. Some powders are well published to do better with mag primers like h110. Some like imr 4227 seem to give better numbers in my experience when using mag. Some people will say 2400 needs a mag and others say no. Rules of thumb help when giving recommendations but only testing give absolute truth.
According to Pearce: “In magnum revolver cartridges, such as the .357, .41 and .44, the powder should be determined before selecting a primer. This is important, as many magnum revolver cartridge powders perform better when ignited with a Standard primer rather than a Magnum primer. This has been proven in several ballistic labs, not to mention my own testing and experience. In one lab test, .44 Magnum loads containing 2400 increased 11,000 psi when capped with a CCI 350 magnum primer versus the same charge capped with a CCI 300 standard primer. As a result, the powder charge must be reduced to stay within SAAMI pressure guidelines, which likewise reduces velocity."
Sometimes this slips by the reloading manual people. A good example is the 1994 #12 Speer manual where CCI magnum primers were used in 2400 data. When Pearce told Speer's Allan Jones about this, at first he was skeptical. Then he re-shot the 2400 data using standard primers and confirmed Pearce's claim was correct. The data was corrected in the #13 manual with the significantly better performance of the standard primer published.
While I have seen these available, I never knew what they are used for or more importantly, when they are needed to be used.
Every reload manual and Loading Data I ever looked at never mentioned Magnum Primers at all. Not even for Magnum cartridges...