So, .327 Federal Magnum for pocket autos?
The .327
almost equals the .357 for kinetic energy - momentum and impact aree, though, are less. That's because the .327 operates at 45,000 PSI vs. 35,000 PSI for the .357. (Not going to get into the apparent disparity between loads at the PSI vs. CUP pressure limits for the .357.)
Similarly, the .30 Super Carry
almost equals the 9mm P for kinetic energy - and again, momentum and impact area are less.
The .30 Super Carry seems to be not quite as potent as the .327, but then you get into things like barrel length, cylinder gap of a revolver vs. solid pistol barrel, etc.
I don't expect to see +P or +P+ loads for the .30 SC, but if you throw those into the mix, the 9mm pulls further ahead. (Disclaimer: some 9mm P pistols should not be used with +P or +P+ ammo.)
I don't see the .30 SC as a
bad round, it's just one of those rounds (like the mutually incompatible short .300 mag rifle rounds Ruger, Win, & Rem introduced) that really don't seem to have much point.
Is that like .357mag for derringers?
https://youtu.be/CKu0RXCB6G4
Notice in the link the guy had his hand over the muzzle(s) of that pistol when he closed the action?