5.7 x 28

[boss-hog2]

Is the 5.7 Johnson & 5.7 x 28 one & the same, and are they based on the 30 carbine case?
I was looking at Redding site & they show case forming dies for the 5.7 Johnson from 30 carbine brass.

 

[SDC]

No, they're two different rounds; the 5.7 Johnson Spitfire is a necked-down 30 M1 Carbine, while the 5.7x28 is a completely new round with a smaller head size. I was able to fire the Five-Seven and the P90 at a demo here, and it was like a 22 Magnum in terms of recoil (but really neat in full-auto). If you're willing to do some wildcatting, you could probably do a .224 BOZ (10mm Auto necked down to .22, loaded with SS109 projectiles) without a whole lot of trouble, other than the dies and a barrel for a Glock 20.

 

[SDC]

Here's a shot of these two rounds next to each other (5.7x28 FN above the 5.7 Johnson Spitfire)

 

[boss-hog2]

5.7x28 & 5.7 Johnson

thanks ever so much-- it is very helpfull