As to military weapons and ammo: two naive questions:
1. Why can't the old .30 caliber carbine cartridge be loaded with a pointed bullet and new powder to perform as a Personal Defense Weapon (PDW) in place of the very expensive weapons from FN and H&K? The old carbine is light and easy to use.

2. Why can't the potent 6.5mm Grendel cartridge be made by necking down the 7.62 X 39 MM Russian cartridge? This would appear to be simple and inexpensive.

-Thanks