Can anyone tell me what a 5.7 Johnson Spitfire is? I saw it in a M1 Carbine look a like.
Thanks.

It is also known as the 5.7MMJ and the .22/30 Carbine.

It is the .30 carbine case necked to .22 caliber.

It was designed by Melvin Johnson in 1963 as a possible assault rifle cartridge.

40gr.bullet at 2850 fps.

50 gr.bullet at 2700 fps.

WC

30 Carbine necked down to .224, which is why some M1 Carbines were modified for its use. Lots of articles have been written over the years about (Melvin?)Johnson's attempt at making it a commercial/military success.

from "Cartridges of the World"-



"It is a very efficient cartrdge, and, like others of this class, gives performance out of all proportion of its size."



40grHP- 14grs.IMR4227 MV 2850fps ME 720ft/lb



40grHP- 12grs.IMR2400 MV 3000fps ME 795ft/lb



50grHP- 14grs.IMR4198 MV 2700fps ME 810ft/lb



some time ago I saw an ad for new .30 carbines chambered in this round- a company in Texas, I think from Israeli Arms.



-tincan