Now I'm thinking.
How much ammo do you think the average gun owner has? Let's say one gun. I bet it's 20-50 rounds. If they own more than one, it's probably 20-50 for each, for hand guns and non high capacity rifles and shotguns. The AR, AK, SKS and Mini 30 type guys probably have 100+ for each of those. Especially the ~.30 cal guys. That ammo is still plentiful and inexpensive. Shoty guys maybe, too. If it's dove or duck season, or they shoot skeet, yeah. 100+. Okay. This is a difficult number to determine.
We're in season six. I think about 550-600 days has elapsed in show time. Would I still have ammo in my existing stock (about 1,000 rounds. Yeah. We have to account for all the mes out here, too.) after 550 days of ZA? If I spent all 550 days here in suburbia? I doubt it.
So, I run out of ammo. I get Zd. Some one finds my guns. Okay, but I'm out of ammo. They'd do best to grab the 9mm and SKS. Maybe the shotties. They're popular. Probably ammo for them somewhere. Or would it be best to grab the odd stuff? Maybe people have passed over that ammo because a .22 Hornet isn't as common as a .22 LR. Then again, there's less of that out there to begin with. Naw. Folks would grab any and all ammo (currency) they could.
What about black powder? Hey, if you can get a suitable ignition and propellant, some rocks or nuts will do for projectiles. Then again, people would snatch up the powder for fire starting.
I think when it comes to it, after 550 days of no new ammo being made, finding any would be getting rare. We'd have to hope for a mil surp score. And even then, those places would probably be occupied by whomever was closest to them. I know I'd camp like a mofo on something like that.