The military has so much stuff available for this type of thing. Lots of different sizes and variations to ammo cans so it should be pretty easy for you to find something to fit your needs. Try and find a military show or swap meet in your area to get the best prices.
Plus most ammo cans will still be water proof, as long as the rubber seal is still in tact. I also have used some wooden ammo crates. They had rope handles and a flip up lid
Plus most ammo cans will still be water proof, as long as the rubber seal is still in tact. I also have used some wooden ammo crates. They had rope handles and a flip up lid