My plan was to set it up that way and at least have fun with it. Figured if I was gonna set it up like an HD gun might as well get some ammo and have it ready as a backup option. I was looking around and I only found #2 and #3 buck and only 2 of those were designed for home defense. The best looking option was made by Remington so that's probably not going to work out. Plenty of good slug options though since 20ga slug guns are still popular for deer hunting. On top of the ammo situation I could only find one used 18" barrel on Ebay. If I keep the 21" barrel, everything else I want for it would run about $100. Any route to an 18" barrel is probably going to cost at least $150, probably more.
Suppose it might make a good woods/camp gun loaded up with decent slugs. Or maybe just keep it as a fun gun.