Re: any home tricks for shorting a shot gun
A couple of years ago a buddy and me chopped an old coach gun from 22" to 18 1/2".
All we used were two pieces of steel secured firmly and evenly on either side of the barrel. We measured and measured again, and made sure that the bar steel was square on the ends.
Then, we used a diamond plated hacksaw blade to cut AGAINST the metal that we secured to either side of the barrels with the flat side of the blade touching the bar steel. You will have some rough sanding to do when you are done to clean up the edges, but it will cut straighter than most blades that are unreinforced will allow. You have to account for the flex in the blade itself.
Go slow! If your cut starts 'veering' off to one side there isn't much you can do to fix it except to flip it over and cut from the other side.