Speaking of alum. cased ammunition problems,I experienced the following with CCI 9mm Makarov ammunition some years back.
Shooting was going along fine, the ammunition was certainly accurate enough. Suddenly, instead of Bang, I got Click. Re cocked,same results. Happened with 2 cartridges. Packaged the 2 dud rounds and including a brief note, mailed them to CCI. After a couple of weeks went by, they acknowledged receipt immediately, the following information arrived. Seemed that somehow, in the production process, the priming compound got separated from a couple of primer cups.The primer compound-less cups got into cartridge cases, and ended up in the ammunition I had purchased. CCI apologized, and sent a couple of boxes of ammunition under separate cover, I assume a better grade, which was about all they could do.