I use two tied together in the back and they carry plenty of stuff for an all day adventure.
These are some kind of Army surplus bag I could`nt tell you what they were used for...
I carry a meatsack with a couple plastic garbage bags for meat with a skinning knife, two small but good flashlights,gps,small plastic medicine bottle full of bright eye tacks,extra string for my bow,lighter,small piece of string maybe ten feet long for blind making or hanging a small grill pig for skinning,thermacell hooked on one strap, I carry three bottles of water in the summer, my camera,bug spray,Bible,extra compass also have one around my neck,extra glove for shooting,and a small container with asprin or such in it. I think thats all. Also can fit a snack in it as well. Recently installed some webbed shoulder straps for comfort not shown in pic. RC