I have a barrel that I wanted to take the choke tube out of and lube it with anti-seize compound before it had a chance to rust or otherwise stick in. The problem was it's a Savage 320 barrel and it's a Chinese copy of a Winchester 1300. After fretting over what tool to order to remove the choke, I noticed that a quarter looked about right. Sure as poop, I got it out with a quarter held in Leatherman tool. It wasn't at all hard either. I don't know if this would work on an old stuck tube but on this new barrel, it worked like a charm...
Hows that for putting in my 2 bits...
Tony