I talked with Jack Mankin and he said a 40 pnd bag was okay, and then I checked the height of the 40 and 70 pnd bags, the 70 pnd bag was 1 ft taller. He asked me the height and I didn't know. The 40 pnd bag was 32 inches tall and the 70 pnd bag was 43.5 inches tall. Jack said the bag should be around 40 inches tall. So I cancelled my order and will wait for the 70 pnd bag which costs the same. I'm sure the 70 pnd bag will take more abuse anyways. So if anyone is looking for a bag, check the height.