Winchester 1300 20 gauge that I picked up at a local pawn shop for $125.00. When I bought it, the stock had but cut short, most likely for a little kid but the butt pad hadn't been finished and there was rust spots all over the steel parts.
So I took it apart, rubbed all the metal and trigger assembly down with steel wool to clean off the rust and give it a scuff for paint. Cut the barrel down to 18&3/4s of an inch and added a sling eyelet to the magazine end cap and put an eyelet in the stock too. The paint I used was a custom blend I made of Dura-Coat. I sanded down the butt pad with a belt sander to match the stock. The final part I added was a green fiber optic bead that attaches to the barrel rib out at the business end. The good thing is too, that if I wanted to put a pistol grip on it instead of the butt stock, its still long enough to meat the 26" O/A length requirement.
I have a bag made from the bottom end of an ACU pant leg that can be closed by using the drawstring and has a shoulder strap. Its big enough to carry 50+ rounds of ammo and stays with the shot gun so if I have to move I make sure I have ammo with me. Just because I don't have a fancy sling with ammo loops for it yet. As for ammo, I just carry 2&3/4 inch bird shot because I haven't gotten any buck shot yet.
This is the bag before it got the strap attached.