Read on a post about a 10mm Magnum round. Had not heard of it and wonder does anyone have the data on that round?

Starline sells brass. https://www.starlinebrass.com/10mm-mag-brass

Reloading Data can be somewhat difficult to locate. https://loaddata.com/Cartridge...Loading-Guide-2/4049

It doesn't appear that 10mm Magnum is officially recognized by SAAMI. https://saami.org/wp-content/u...roved-12-13-2022.pdf

That means research your loading data very carefully and know how to watch for pressure signs. There will be no official maximum pressure for a non-SAAMI recognized cartridge.

From what I've read about 10mm Magnum, the goal was to get closer to the .41 Magnum cartridge.

10mm Auto, and 10mm Magnum (rimless cartridges) headspace off the case mouth, and both of them require a taper crimp. Under recoil, the projectiles can "jump crimp" and come partly or completely out of the case mouth. This is generally a revolver problem/concern with the end result if crimp jump happens, is a tied up inoperative revolver.
If the projectiles move forward out of the case mouth in a semi automatic, they can/will jamb up inside the magazine.
I reload 10mm Auto (not 10mm Magnum) for both a semi automatic and a revolver, and have never experienced crimp jump.
My reloads are apparently not vigorous enough to have crimp jump occur.

I suppose there "might" be some obscure factory built semi automatic firearm chambered in 10mm Magnum, but it is unknown to me.

Most 10mm Magnum users are the folks that like to "tinker" and get their 10mm Auto revolver rechambered to the longer 10mm Magnum.

So if you are using/considering 10mm Magnum and have a serious usage for the cartridge such as self protection against large animals, the .41 Magnum, and .44 Magnum revolver cartridges which
are rimmed for headspace control, these have roll crimps, and are much less likely to experience crimp jump, and potentially locking up your revolver when you absolutely need it to function.

I'm no expert authority on reloading or cartridge design, but at least to me, 10mm Magnum was a "solution" that nobody needed or really wanted.

There are few semi automatic pistols chambered in .41 Magnum and .44 Magnum. Desert Eagle is one example.
Also, no 10mm Magnum semi automatics that I am aware of.
Most people wanting .41 Magnum and .44 Magnum power levels in a handgun are using revolvers. (or .480 Ruger, .454 Casull, .460 S&W, .500 S&W plus the Linebaugh cartridges, all in a revolver)
So why pick a rimless cartridge with a taper crimp (10mm Magnum) when .41 Magnum and .44 Magnum revolver choices, both for the gun and ammunition, crush the competition from 10mm Magnum.

If you just want a 10mm Magnum for the enjoyment of another cartridge choice, that's fine.
But if your life might depend on that 10mm Magnum revolver, .41 Magnum and .44 Magnum are better choices.

Not interested in having a 10mm Magnum just curious about it never having heard of it. Personally like 10mm as wood carry. If I wanted more I'd go 44magnum.

I don’t know anything about the 10mm ‘magnum’. I do agree, if one wants to get to those performance levels, it’s much easier to do with a revolver. That’s kinda how I get there.

One may ask, why mess with a magnum semi-auto? Some are more familiar, logical choice from owning similar guns. There can be a weight benefit, less. Yeah, you usually get a few more rounds, with faster reloads. Oh, and it’s bigger than your buddies gun.

quote:

Originally posted by abnmacv:
Read on a post about a 10mm Magnum round. Had not heard of it and wonder does anyone have the data on that round?

The 10MM Magnum cartridge was introduced in 1992 along with the Auto Mag IV pistol



The Auto Mag IV pistol held 8 rounds of ammunition in the magazine with an additional round of the chamber. The barrel length of the Auto Mag IV was 6" or 8 3/8"



The Auto Mag IV (also Factory availble in 45 Winchester Magnum) never really took off. Conversion barrels were made available in 44 AMP and 357 AMP chamberings giving the pistol some additional versatility

As already mentioned by cee_Kamp the 10MM Magnum cartridge is a stretched version of the 10MM Auto cartridge. The intention of the cartridge was to bring 41 Magnum performance to an Auto Loader, in this it succeeded very very well

Fortunately, Smith & Wesson had introduced the Model 610 revolver just two years earlier in 1990



While chambered for the 10MM Auto cartridge, like all Smith & Wesson revolvers that are designed to fire rimless auto ammunition in moon clips, the cartridge actually head spaces on the moon, clip not the case mouth. This is why shorter cartridges like the 40 Smith & Wesson can also be fired in the model 610 revolver.

This allows hand loaders, who are working exclusively with resolvers, to utilize any style of crimp that they wish

The 10MM Magnum is a wonderful revolver cartridge for Self Defense, especially when utilizing one of the various snub nosed revolvers. This Smith & Wesson Model 310 Night Guard is a fantastic example of this. With a frame constructed of Scandium alloy to reduce weight, along with it's 2 1/2" barrel it makes a easily concealable revolver



Using rimless cartridges in revolvers has the added benefit of speed and reliability when using fully loaded moon clips

The 10MM Magnum loads gain 200 - 500 FPS advantage over the same projectile when loaded into the 10MM Auto cartridge,obviously depending on the projectile/powder combination.

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