I got the bottom part of a 3AA-2400 weld tank that I made a B.Ball Mortar out of. I want to make another one now and put the powder chamber in the tube. I want to cut a 6 in. hole in the bottom for the chamber, How can I do it, Dont have a lathe that big. I layed it out for a 6 in. circle and drilled 4 holes but it 3/4 in. thick and thats not going to work, Thanks for the help, Joe