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

[JASmith]

What the .30 carbine has going for it over the 9mm is being able to do aimed fire out to 100m. Not sure that the 9mm would have the accuracy let alone the energy down range that the .30 carbine would.

Any PDW has to have the ability to engage targets out to 100 m.

Concur with need for a PDW to be able to to engage targets out to 100 meters.

The perception of gross inaccuracy of the 9mm comes from the 4 to 5 inch barrel and a firearm designed for one-handed use.

A 20-inch 9 mm barrel would add about 200 fps and yield a 100 meter velocity very close to that of the pistol at the muzzle. Further, a 100 yd zero would keep the bullet within about 5” of the line of sight out to past 140 yards.

Assuming both are FMJ military rounds, the larger diameter of the 9mm bullet would result in more rapid incapacitation in hits away from the CNS or major bones.

Both being carbine platforms, the hit probability would be about the same for each.