Jens Theodor Suhr Schouboe patented his original semi-automatic pistol in 1903.

It was a simple blowback design with an unusual wood core projectile with a metal jacket.

The Schouboe was direct blowback, so it could not handle the energy of a traditional 45 caliber cartridge.

To get around this, Schouboe made the bullets have a wood core with a metal jacket so that the bullet would be light enough that it could be fired out of the pistol and the pistol would eject safely.

The pistol was rejected for not having sufficient wounding ability.