The RPG series (RPG-2, RPG7) use a vertical firing pin, hit by a swinging hammer in the trigger guard-pistol grip unit. This strikes a primer in the rocket’s tail (also vertical ie, diametrical).The rocket has a positioning key located at the muzzle of the launch tube, to ensure the primer lines up with the firing pin. That is for the “live” rocket. The training sub calibre device uses the same ignition system, only that the “charge” consists of the combined blank/tracer round, with the primer flash going at 90 degrees both fore and aft, to ignite both cartridges simultaneously. The bulleted cartridge sends the tracer to the target (to ensure ‘target acquisition’) whilst the rear blank ignites the 12gauge booster, to give the rear tube “flash” and blast. The cases are pressure die cast with the alloy as a unit, then the connecting holes are drilled through from one or other of the cases, the side primer hole already formed in the casting, the entire unit is primed, loads introduced for the bulleted and the blank cases, the bullet seated, the blank crimped, the side primer lacquered, and the item is ready to go. Note that the cases are unprimed, unheadstamped normal cases, with a substantial amount of Alloy flowing into the pockets, and between the cases, allowing for the primer chamber and “T” connection to the drilled holes (through alloy and case web) to give the “fire holes” to both cases. (IAA Forum)

Close-up view (600% scale)