The M1 Carbine is the standard by which all PDWs are measured.

[FloorPoor]

I would rather have a 9mm carbine than 30 carbine. Both have an effective range of about 100m, but a carbine that accepts the same magazines as your side arm makes sense.

A 9mm fired from a 16" barrel packs about the same energy that a .357 mag 4" barrel has at the muzzle.