Hello Friends! Thanks for viewing my post. I had a local pro. gunsmith do the work. Here's what I had done. He cut the first 2" off this made the barrel a cyl. bore and the smithy made an arbor bit that fit perfectly to the 410 bore an made a beautifully done target rifle crown. He then drilled an tapped the breech an ordered the weaver scope base, weaver rings, an the bushnell sportsman 4x32, the smithy also did a little work on the hammer, just a tiny notch so I could set the hammer spur in place. My gun is a pardner wood stock all blue. It now has a 24" barrel cyl. bore which I'm finding out shoots very well! I did my research before ever starting this. I've only had the chance to shoot for a couple hours at a local range. Not knowing where the gun would shoot I shot at 25yards off bench. So far I've found the 2.5" winchester rounds give terrible accuracy, although I did use them to get me on target. The next round in the breech was the remington 2.5" slugger, A good steady hold an crosshairs centerd put that slugger dead center! I was amazed and thrilled just knowing at this point the money spent was going to be worth it. Tried another remington slugger, and just about the same. Next I shot the brenneke silver slug. Man what shooters these german slugs are! These slugs printed about an 1/2" group @ 25 yrds. These brenneke cost more, but you get what you pay for. Keep in mind also I had the work done by a man in the gunsmith buisness for many years. And I really think that crowned muzzle makes a difference. This is my deer gun, some folks may frown on that, but they don't carry the shoulders that I have to. Anyway, thanks for your questions and your comments. Have a great day! <><