very interesting and informative..I've got a video put out by Benelli that shows their cryo-treatment of shotgun barrels..in the video it looked quite complicated but ur way is MUCH simpler and attainable...thanks much !!!
You might consider Northern Tool. they have a 2"x27" grinder/belt sander combo for under $100 and as mentioned before there's harbor freight, craig's list and
ebay also has some belt sanders. Good luck!!!