Bought 2 cly. tanks, a oxg. and a carbon dioxide, Both are 9 in. OD, cut into on a big band saw. walls are .275, this gives a bore of 8 1/2 inch , . Bowling balls are 8.563 in cold state, The bore is 1/16 under size and out of round. , Need that big 3A 2400 tank size. Looks like I got some big melting pots or wind chims.Darn, got 22 balls to shoot.