[@Section] Holy crap, dude. You sure you can keep up with that? o_0 I'm not going to say you can't, but that's a crap load of writing for every post.

I think you have too much ammo. A tank collector collects tanks for display, not for shooting other tanks, and unless you have a source saying otherwise, I don't think anyone can buy or own live military-grade tank shells. Belt-fed ammunition, maybe.  Either the collector had a tank and ammo stolen and imported illegally (the US government would NOT be okay with that cargo going through customs), or you raided a military base that housed tanks, which begs the question, why didn't you get a better tank?

I think this is taking place in the US, so Makarov pistols and MN rifles are actually pretty hard to come by. Your odds of finding a .45 ACP 1911 handgun and a Remington 500 rifle are way higher, even in a crisis, especially after so many years. Then again, a plausible explanation is that the government declared a state of emergency and confiscated every weapon owned by people, leaving behind old guns.