I just watched a video of the new U.S. Air Force rifle training course. Part of the training is to mix dummy cartridges in the magazine of live rounds so the trainee has to practice clearing the weapon. In the video, one can see a 5.56 dummy cartridge on the ground with empty 5.56 casings. There is no primer and the “bullet” is orange, short, round-nosed and plastic in appearance. Is this an issue cartridge with an “M” number, or possibly something locally sourced?