A little background, I am a auto mechanic by trade and and an amateur gunsmith/machinist I recently got a 12ga SxS that was`cut down with a hacksaw, the barrel is 20+" I saw the choke reamers and taps but I do more rifle than anything and cant spend $300 on tools for a 100 gun (Boito made in Brazil). What is the correct way to shorten a barrel (I know the cut on mine isn't straight) How can I fill the space between the barrels? Is there a cheaper way to install some kind of choke. I dont mind spending a little money, I consider this a practice gun and am more concerned with learning than anything else. I only have 1.5" to work with (I want to keep it about 19" just in case) Any help would be appreciated.