I have priviledge of getting an A5 old school 3" gun. I want to make it into a duck gun. It is a 95% gun but it has sentimental value to me. Have always wanted one. Bluing I could care less about, not gonna dip it just let it ride. Barrel is my issue. What are the best choke tube barrels out there now with a thread pattern that is easy to find chokes for? Hastings? TIA.