.25/30, .257/30, 25 Johnson?

I shoot and reload for the 5.7MMJ Johnson “spitfire” carbine. A good friend of mine who works at a local gun shop told me that a bag of brass for the 5.7MMJ showed up and he picked it up for me.
When I opened up the bag, the brass is not 5.7MMJ. It is still based on the .30 Carbine,but is 25 caliber. Standard .30 Carbine brass was used.
The neck and shoulder is identical to the 5.7MMJ but has been opened up to take a .257 bullet. The brass had been once fired.
A light .257 rifle bullet would be hard to find that would perform well and fit into the carbine magazine.
I’ve not been able to find any real data on this cartridge.
Any ideas on the history of this cartridge?
Thank you.

A M1 carbine chambered for a cartridge made from a .30 Carbine case necked to .25 caliber was developed as early as 1965 by Johnston-Tucker Arms Company of St. Louis, Missouri, and put on the market as the “.256 Johnson”. You may find some sources indicating that this was another name for the .256 Winchester Magnum, but they are incorrect. This company also offered loaded ammunition, which means that there may be a box of these cartridges hiding somewhere…

Thank you for that info. I’ll do some research now I know what to call it.

Most of us are familiar with the 5.57 MMJ and all of it’s variations, some of which preceded it and some that followed. With a tiny case like the Cal .30 Carbine, there’s is not much that can be done to make one wildcat of a certain caliber different from another. If 10 wildcatters were asked to design a 25 caliber cartridge based on the carbine case, the odds are that more than 5 of them would be nearly identical.

The .256 Johnson is certainly not the only 25 caliber wildcat using the carbine case. And, it won’t be the last. It may have happened that Johnson/Tucker were the first to advertise it. But, it’s no more legitimate than the .25 Hokey Pokey or the .257 Car Max, or any other name a wildcatter may come up with.

I used to collect wildcats (I don’t anymore) and the proliferation of similar, if not identical, cartridges was both an attraction and aggravation. Based on posts on several of the Shooting and Guns Forums, it hasn’t eased up any at all.

The 256 Win Mag uses the 357 Magnum case so it’s not even close to the 256 Johnson. It would be more akin to the 25 Super Short, which is one of my own wildcats, BTW.

Now I’ve gone and done it. Sucked back into talking about wildcats.;-)



Regarding bullets for the little .25, there are some short .257" dia. products out there for use in the .25-20 WCF and .256 Win. Mag. that would probably work for length. It would be interesting to see what was used in the original Johnson loads Fede references.

Also, it might be worth mentioning that confusion between the .256 Johnson and the .256 Winchester Magnum may come from the fact that Universal produced the Ferret model M1 Carbine type variant in what I assume to be .256 Winchester Magnum caliber. The little published info I have on that rifle indicates “.256 Cal.” with no mention of the “Winchester Magnum” part of the designation. The listed velocity of 2,820 fps with a 60gr. projectile would seem to jive with contemporary ballistics claims for the .256 Win. Mag. and likely a bit beyond the prudent/believable performance of a .30 Carbine based cartridge.


Here is a picture of .22 and .25 caliber wildcats made in 1943 by an anonymous individual (surrounded by a .218 Bee at left and a .30 Carbine at right). I don’t have more information at the moment.

That photo was published in an issue of “American Rifleman” in their “Dope Bag” section. I don’t remember any additional data beyond the photo and its caption.