DIY weapon systems..... in a Mad Max world

All political and religious ideaologies aside, you've got to admeire these guys.
Fighting tanks with slingshots.
Gets my respect.
Fuck yes.
 
My basic 5 gun battery would be:

1-.22 pistol- accurate, light duty for practice.
2.-big pistol- any caliber useable to put some serious hurt on an intruder in the house or "your bubble" when out in public i.e, .45ACP, 9mm, 10mm, 40 S&W....
3..22 rifle- accurate for practice of big rifle and light duty game getting.
4 big rifle-preferably .30-06/.308 for ease of acquistion of ammunition in case of pinch. Lots of surplus if you can get your hands on it.
5. AR- preferably in 5.56, but any cartridge you can get your hands on in bulk. I reload so bulk isn't an issue. Neither is accuracy. This is for when you need more than 1 shot per 5 seconds. The 'horde' is just too thick. Practice should be kept to a careful minimum though as it is easy (and way too much fun) to overpractice and expend resources.