I think the OP's premise is that all you can have is 200 rounds - no .22 conversions, no inventory or going to Walmart. Which would you choose?
I would take the 870. With only 200 rounds, I would always opt to lay low, retreat, and avoid all confrontations if possible, saving the ammo for feeding my family. An AR pretty much eliminates shooting birds, especially if they're flying. Not that you can't shoot one, but if it takes 2 or 3 shots, then you'll feed your family 1/2 to 1/3 of the days that I feed mine.
Besides if I'm already living in a tent, there are no assets to protect other than me and my family's lives. I'm not going to get into a gun fight over a tent.
I would take the 870. With only 200 rounds, I would always opt to lay low, retreat, and avoid all confrontations if possible, saving the ammo for feeding my family. An AR pretty much eliminates shooting birds, especially if they're flying. Not that you can't shoot one, but if it takes 2 or 3 shots, then you'll feed your family 1/2 to 1/3 of the days that I feed mine.
Besides if I'm already living in a tent, there are no assets to protect other than me and my family's lives. I'm not going to get into a gun fight over a tent.