Nasty little trick at Appleseed.
What you are seeing are foam plugs inserted in empty brass cases. The instructors in Appleseed use them to create random failures so we can practice clearings. Somebody else loads your magazine mixing the good ammo with the “foamies” so you do not know when you will have a failure.
Nasty trick, yet instructional.
That’s how we learn to remain calm and do our jobs. Making failure just another step.
Awesome innovation
Ball and Dummy drill. There’s no school like The Olde School.