Wells,
Let's see here...I'd take me one of them 9mm carbine barrels and have Clymer or
Manson grind a chamber reamer to accommodate a blown straight out .223 case.
Neck ream the brass neck/mouth a few thousands and load 'er up...
Proabable have to use .355 bullets or swage down .357s for the heavy weights.
Just a passin thought....
Su Amigo,
Dave