The Norm carbine was designed by Mr. Norman of BSA. It was intended for the SOE, and Norman had previously designed the Welgun submachine gun. In terms of design, the Norm carbine shared traits with the Welgun. The Norm was cocked by a large, milled slide-like component. The change lever was on a pivot which had to be held down by the right thumb. The Norm did have a folding foregrip, but it was designed to be held in a very unusual manner; the firer's left arm would pass underneath the barrel and grip the foregrip with their left hand. The Norm carbine was trialed but never fielded.