Does anyone have any information on this Wildcat? I'm curious about a 223 caliber on this Miniature Short Mag.

Check Wolfe Publishing's "Wildcat Cartridges" and their "Pet Loads" for the .308x 1.5. Should be close enough to start with.

I've never heard of the 308x1.3", but the 1.5 inch version was pretty popular for a while. None of the references I have make mention of a 308 case trimmed to 1.3".

I love wildcats as much as the next guy, but I wouldn't go to all that fuss when the 1.620" 223WSSM already has it covered and the 22BR IS a 1.5" 308 case, necked down. IIRC, the 22BR uses a small rifle primer pocket, but don't quote me on that. Your thought would be the same thing, trimmed .200"...not sure why you'd want to do that when it may lead to feed issues and there are already two super-hot 22's available in that length.

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Ask me about QDMA.

A small group of us are creating a prototype semi-auto handgun which can handle cartridges such as a rimless 357 Magnum based upon the 7.62x39 cartridge. We have also explored a 223, a 256, a 284, a 312, in addition to the 357 Super Auto Magnum. Then several folks have come along suggesting the 308 as the parent case, but it is much too fat which could cause jamming problems. We are intentionally restricting the length to 1.3" so that cartridges which are really much too powerfull for a semi-auto can be avoided. We originally began with the 10mm as the parent cartridge, but decided that the 7.62x39 would offer much more versatility without being too much cartridge. And of course the 308x1.3 would most assuradly be too much cartridge.

Well, I can tell you right now I'd have zero interest in a small-bore, high-velocity, rimless auto pistol. Sounds like nothing short of a flame-belching monster with little or no redeeming qualities...aka the 30 Carbine from a revolver. There is a long history of failed small-caliber, high-velocity pistols, with ample proof that larger caliber is the way to go. As with any "new" gun project, it has ALL been done before.

However, I think your choice of 7.62x39 parent brass is a lousy one, for the objective you've set. The obvious choices would be the 204 Ruger and 6.8 SPC. Both have a smaller case head and less taper, as well as being more readily available in reloadable brass. Of the two, the 6.8SPC would be my choice, hands down.

Good luck with your endeavor. I'm sure some folks would be interested.