The case.
Even when it is boxer primed and thus potentially reusable in its present form, the brass case is, at the time of use, disposable. It is unfortunately an expensive part of the cartridge and from the standpoint of a national industrial policy, uses copper and zinc which are both strategic materials needed in other uses by a wartime economy.
There has been some use of alternatives like aluminum and steel, but they are only marginally cheaper and are also strategic materials.
I think the achillies heel of individual weapons is the case and the next great leap in firearms technology will not be taken until we come up with a way to dispense with a metallic case to serve as the bottle for the powder, carrier for the primer, and gas seal for the bullet.
Even when it is boxer primed and thus potentially reusable in its present form, the brass case is, at the time of use, disposable. It is unfortunately an expensive part of the cartridge and from the standpoint of a national industrial policy, uses copper and zinc which are both strategic materials needed in other uses by a wartime economy.
There has been some use of alternatives like aluminum and steel, but they are only marginally cheaper and are also strategic materials.
I think the achillies heel of individual weapons is the case and the next great leap in firearms technology will not be taken until we come up with a way to dispense with a metallic case to serve as the bottle for the powder, carrier for the primer, and gas seal for the bullet.