Quote:
Originally Posted by 243winxb
Remington primers- https://www.ssusa.org/content/reming...istol-primers/
Indeed, Remington’s ballistics tables list the recommended primers for each caliber that Remington loads, handgun and rifle. The 1½ primers are listed for the 25 Auto, .32 S&W, .32 S&W Long, .32 Auto, .380 Auto, .38 S&W, .38 Short Colt and .38 Special. None of these cartridges exceed 25,000 psi peak chamber pressure limits. Surprisingly, the 1½ primer is also listed for the 9mm Luger, the 9mm +P and .38 Super. These latter calibers are not low pressure. The 9mm Luger has a SAAMI (Sporting Arms and Ammunition Manufacturers’ Institute) pressure limit of 35,000 psi, and the +P version’s limit is 38,500 psi. The .38 Super has a SAAMI pressure limit of 36,500 psi. These compare with the .357 Magnum and .40 S&W pressure limit of 35,000 psi, and the .357 SIG’s limit of 40,000 psi. If the 1½ primer is not appropriate for the .357 Magnum and .40 S&W, how can it be appropriate for the 9mm, 9mm +P and .38 Super, which have the same—or even higher pressure limits?
This has caused confusion among some reloaders, myself included. In fact, I was unaware of this warning when I first bought 1½ primers and used them in 9mm Luger loads. I thought the 1½ primers were “standard” primers, and the 5½ primers were “magnum” primers, since that is how they are listed in many primer charts. |
This is an epiphany I have had recently. I have heard the argument for the thicker primer for the higher pressures, but as you stated, 9mm and 40 both run pressures the same or higher than 357 mag, but I have never seen any load data call for mag primers in either, so that debunks that argument.
Only argument I have heard that does make sense is that some powders need a hotter flame to burn consistently. And that some ball powders such as H110 may burn fine at normal temps, but in cold weather environments, that is when you really start to have hang fires and the like and a mag primer will take care of that.
Other conclusion I have come to. Magnum in a cartridge title is used in a different context than Magnum in a primer name. 2 different uses of the term. In a cartridge, it was really just a marketing name to sell products. In the primer, it really means a hotter flame and also varies from manufacturer to manufacturer.
For example, a .270 Winchester runs higher pressures than a 7mm Rem Mag. And as you stated, the 9mm and 40 may run higher pressures than a 357 mag and 44 mag.
Rosewood