For people who cast their own bullets and reload their cartridges... there is only one choice. The M-16/AR-15 needs copper clad projectiles which are difficult to make yourself. The AK-47 is very happy using homemade cast, and heat treated bullets with gas checks made out of aluminum roof flashing. I have enough primers to last for years, but even those can be made at home if necessary. So far powder has not been that difficult to find, but I have a lot of that as well.
Sumthin to consider.
Ak47 it is, then.