I don't like carrying and measuring loose shot, in bags or other containers, in the field. I used to carry premeasures shot in cane/bamboo tubes and form paper shot cups at the muzzle. Tube can be seen here,
Now I carry premade shot cups/cartridges in a tin in my shot pouch/shooting bag, as seen here, in lower left corner,
That tin holds 8 1oz squirrel loads. For turkeys the cartridges are longer as they hold more shot, but concept and use is the same. When out for turkey or small game the ball bag is left home and both tins stay in the bag, when out for deer, the tin of shot cartridges comes out, the tin of wads stays, and the ball bag goes in.