Here's some quick drawings of my AA 260 bin. I realize the pics are out of order but I wasn't going to re do the drawings.
1 - shows a cross section of the bin showing how I stack 2x4's or 2x6's to rise the height inside the bin to stack the coal towards the dog house. This was done by using 2x4's on the side wall leaving space to slide the others into the groove.
2. Shows 1 possibility where you would just have the sloped section near the auger only so it would self feed.I added the 45* sloped floor if you really want to go that route. I don't have that in mine.
3. Shows an overhead view of my bin. Forgot to add the double access door located near the number 3 to allow me into the bin. Those doors are closed when the bin gets filled and leave a 4' tall open space to the bottom of the floor joist so one can climb out of the bin after packing it full.
When the bin gets filled, I leave about 18" of vertical height in the removable 2x4 's shown in fig 1. The bin self feeds the auger for quite a long time. As the level goes down, I start shoving coal from in front of the access doors towards the dog house stacking it up high above it. And continue to shovel as the level goes down. The 2x4-s allow me to empty the bin down to about 1/2 to 1 ton before requiring a refill.
4. Shows hot to put a barrel over the auger. Set it up on cement blocks so the coal can feed from the sides when the bin is full. 1 thing I noticed with this setup is that as the bin goes down, you constantly have to be shoveling coal into the barrel.
The shoveling that I do takes all of about 5 minutes 1 times per week.