I have an Older Winchester Defender 1300 with the 18 inch barrel and a full length magizine tube. Does anybody make a longer barrel such as a 24 or 26 inch that is threaded for choke tubes? I want to go hunting with a shot gun but I dont want to purchas a new one right now.

I spoke to a local gunsmith and he told me that he could install a standard magizine tube and then i could use any standard winchester 1300 barrel on it. But If I was going to spend all that money I would be better off buying a new shotgun.

I have the 1300 "camp defender" version, 22" barrel with rifle sights and choke tubes. I'm accustomed to doubles with 26 and 28" barrels and the pump with 22" has similar handling. The choke tubes make it a very versatile gun. I haven't tried any of the rifled choke tubes but with the smoothbore improved cylinder tube I get 4-6" groups at 100 yards with the cheap Wolf brand slugs and that is with very coarse open sights. The improved-modified tube gives tight patterns with 3" mag Remington Heavy-Shot loads while the improved-cylinder with 7 1/2 trap loads is great for grouse and bunnies.
If I were honest with myself that is the only gun I need to own for all of my hunting. But why have just one gun when you can have MANY? Anyhow, if you can find one of those barrels it will work fine with your present magazine. Otherwise, I'd second the vote to sell that gun and get a new one. Money spent on modifications and customizing never comes back when you sell or trade a gun.