We had these sandbags custom made after three years of fighting with canvas duffle bags. Our new bags are olive green in color, made of 1000 Denier Cordora Nylon, double stitched, and have hefty daisy chain handles.
The inside of the material is coated with polyurethane, which helps prevents dust from wood pellets, gravel, or whatever filler is used, from escaping.
Sandbags come empty. Seal the top using cable ties or parachute cord, and duct tape.
APO is fine, but sorry, no Internation Orders.