Make sure to ask what thread and brand of tube he is able to thread it to. Colonial is a no way, no how. Their thread is too fine and they tend to shoot loose. They are also not recommenced for shooting hard non toxic shot through by other experts in the business, besides colonial themselves. I had a Browning A5 Magnum 12 that had Colonial tube that had been installed. I was shooting steel through it. It shot loose very fast and after cleaning and thoroughly tightening. The tube broke off after only a few shots, right even with the threads. I was lucky and got it out. I called Colonial and they denied warranty. They gave me a butch of mumbo-jumbo about not using proper choke tube lube made specifically for choke tubes. I told him in no certain terms, to stick their choke tubes up his @$$. Traded the gun off that same day. That's after I called a well qualified choke tube expert and he advised against ever shooting steel or other hard non toxic shot through Colonial thread pattern tubes.
Another thing, some guns don't have enough meat (too thin barrels) to install anything but thin wall tubes. Many times you can not shot hard non toxic shot through these thin wall tubes. Just a heads up in cases this would be the case in your situation. You wouldn't want to go through all that work, with the objective in mind of making your gun steel shot compatible. Then find out you can't shoot steel through it anyways. Make sure to ask plenty of questions. You want somebody well qualified. Nothing worse then getting tubes installed and the gun shoots a foot left of point of aim. Good Luck
I can't wait to fire my old twenty at some bird that decided to call state ground his home.