magnum primers

[bucktracker]

Bought 1000 cci magnum primers for large pistol after waiting too long for standard large pistol primers to become avialable. I heard one could use magnum primers to substitute standard primers, as long as one stays well below the max load. I'm reloading 10mm and 45auto. Any thoughts?Bad idea?

[CJS3]

Just reduce the listed loads by 10% and you should be okay.

[m25operator]

Cj is pretty much right on, but magnum primers may not fire in modified firearms with reduced hammer force. Side note, sometimes you get a more complete burn, and therefore a cleaner bore to deal with, less unburnt powder.

[SpottHogg]

As was already said you should take care into reducing charge weight with themIf you are already at max or close to it. If you are not then try them without changing the powder charge Ive had it make no change in point of impact or velocity in both rifles and pistols, especially pistols. The biggest point to consider is the "magnum primer" has a thicker and/or harder cup alloy. This is to resist pressure peircing of primer with the elevated pressures of magnum calibers. This characteristic requires more hammer energy to ignite the magnum primer. In your case, based on my experience, CCI require the most hammer force to set off. Most of the time a semi-auto pistol (commonly using a coil type hammer or stryker spring) will be less vulnerable to failure if the springs are stock and not worn with very heavy use. But a revolver (like a S&W) using a flat or leaf hammer spring is very vulnerable due to spring weakening common in flat springs due to constant load and flexing. Not to mention the flat spring is easily modified by the end user and you may not know if that used gun was played with. Good luck with them, I hope they go BANG everytime!