The "Ord Bomb" is the proof of final acceptance by the Army Ordnance Dept's in-house inspector at Colt.
It indicates two things, 1) that the firearm meets are contractual requirements (and thus will be paid for by the government)
and 2) that it is ready to ship to a depot for issue to troops .......
Not all Commandos had the Ord Bomb applied. Only those that went to the US Army for distribution.
Others went out unmarked and were shipped to the Defense Supply Corporation for issue to Defense Plants, Police Dept.'s and other qualified organizations that applied for purchase of firearms outside the US Army supply system.
Sale of all NEWLY manufactured firearms during WW2 were strictly controlled and were basically rationed on an as-needed and priority basis.