5.7 Spitfire?

[Sandmann]

Does anyone know the history, specs, and ballistic effectiveness of the 5.7 Spitfire?

Is it a manufactured round or wildcat? If its manufactured, who manufactures it?

What are its specs?

If its a wildcat, what is the 5.7 Spitfire's appeal when there are so many potent rounds such as the 5.45x39 and 5.56x45 and the 5.7x28?

 

[NMshooter]

An attempt to do something with some of the millions of M-1 carbines laying around...

.30 carbine necked down to shoot a .224 bullet.

Not very popular.

 

[grendelbane]

It is not very popular, I suspect it is one of those cartridges that was just ahead of its time.

Still, it is an interesting concept. It has managed to linger on for many years.

It is more potent than the 5.7 x 28 mm cartridge, which is still not saying very much.

 

[Gordon]

I fooled with one of these, left to me by my dad, who fooled with it 15 years before I had it. I no longer fool with it, I have no time for all the fooling it requires
A rimmed K-hornet if there ever was one. They DO feed quite well because of their shape. The gas system requires A Lot of fooling to function one of those JOHNSON 5.7mm Spitfires

 

[Sandmann]

It must be why its such an obscure and little known round. I love the M-carbiine, and had heard about it doing some online research. I was hoping to get some anecdotal feedback to see how it performed, but so far it seems as if few people are singing the 5.7 Spitfire's praises.

 

[Sylvilagus Aquaticus]

Yeah, it's Melvin Johnson's baby. Johnson, of Johnson M1941 rifle. (See Marines, Pacific Theater, WWII).

He thought it'd make the M1 Carbine into a varmint rifle. Seems like IMI was/is chambering some of the new carbines they make in it.

You're right, it's pretty much a K-Hornet for all intents and purposes, for a semi-automatic.
Fulton Armory is selling 5.7 Spitfire barrels and conversions, too.

<edit to add>
http://www.reloadbench.com/cartridges/wmmj57mm.html
http://www.thegunzone.com/carbine-wildcat.html
Regards,
Rabbit.