Depends on the size of bean seed you are planting. 12 might be right for an 2200 count/lb bean size but way over board for a 3500 count/lb bean size. What bean size are you planting?
Feed gates at bottom of seed cups should be set to middle position for the majority of food plot seedings.
If you have an acre counter on the drill, then use it to calibrate.....put in the amount of seed you want to plant in 0.5 ac.....choose the 12 setting....start drilling....if you run out before 0.5 ac, the drop to a 10 setting and repeat.....if you run long, then increase setting to 14 and try again. Just check the hopper about each 0.1 ac to make sure the seed cups are full and each is planting. When you get it figured out, take a magic marker and write the setting and seed information on the underside of hopper lid for future reference. Seed size and density may change from year to year so you may need to tweak the setting from year to year.
One other comment....on these drills.....always move the lever to a number well above your desired setting, then move it back down to your setting....this consistently takes the slack out of the linkages and makes drill adjustment more consistent when tweaking.
Seeding rate can also be determined by measuring the width of opening on the side of the seed feed (the cogged metal cyclinder on the feed shaft) in the feed cup (the metal bowl where seed meters through), if the lever linkage is way out of whack. Seed feed opening (distance between end of cog cylinder and edge of feed cup) should be about 3/8" to 1/4" for each feed on the drill for planting beans or cow pea.
