I have many thousands of demilled magazines, mostly struck with a hammer or an axe on the body somewhere. I have, on an as needed basis, cut the magazine bodies short so they have a 5 round capacity, which is the maximum capacity here in Canadaicon. I use these in my Sterling police carbine, and up to date, everyone has performed flawlessly. It would almost seem like the Sterling is more forgiving of the magazines than the sten.