The 9x51mm SMAW:

Great Brittain produced a 9mm aiming device for the Schoulder launched  Multipurpose Assault Weapon (SMAW). The 9mm round was fired from a special spotting rifle, which was positioned at the right side of the rocket launcher (see image)

reusable SMAW rocket launcher

A 7.62x51mm cartridge case was necked up to 9mm and at the base of the round, a (blank) .22 Hornet cartridge was placed. When the round is fired, the bullet is pushed into the barrel and the .22 Hornet case is pushed backwards, reloading the spotting rifle.   

The subcalibre was produced in two different versions, a tracer and a tracer/spotter round . The tracer round is marked with a red bullet tip. The tracer/spotter round is approved as the L3A1and can be reconized by a red over yellow tip collor. (see images)

           

Tracer- and tracer/spotter round.             headstamp:RG 83

The carton boxes: