No, not really. The macaroni are formed by squeezing the dough through the openings, while the cartridge cases are made by stretching small metallic disks into cylindrical shape (and then stamping the bottom to make it flat and have a proper rim), so it's impossible to repurpose the pasta-forming machines into the casing-making ones.

But it is an urban legend of sorts, along with "baby strollers with chain tracks instead of wheels", and shows how little most of us know about industrial manufacturing.