I, for years, used a very big gym bag. Inside that I carried an old metal tackle box with cleaning stuff, screwdrivers etc. It carried just about everything but ammo. I carried ammo in a 50 cal ammo can.
This year I finally changed. I bought this from Smilin' Larry -
MidwayUSA Competition Range Bag
It's giant. All the cleaning stuff now goes into a big, side pocket that zips open to fold out, has internal pockets and elastics etc. It carries guns, ammo, first aid, eyes and ears, rags, binocs, camera, in college I had apartments smaller than this thing. It comes with two nylon gun bag/rug things, a lift out ammo carrier, place for targets or other papers. There's a video on Midway's site and several video reviews on YouTube.
Comes in all your favorite tactical colors..
Now I've got a 50 year old metal tackle box available for something else.
Sgt Lumpy