Find a older 870. I think they. Hanged the barrel mount at some point. I like the older one. Find one, file paper work, buy oem 14" for around 200. Done.
I used to buy old 870s for $200 all day. They have gone up but you can still find them around. Buy one with a long barrel cheaper than the tactical ones. Then sell the old original barrel.
I have also cut barrels, filed them smooth and installed a bead. Easy enough if you take your time but not as nice as the original barrels.
This one started as a regular 870. This barrel is too short and it now has a OEM 14". But you can buy old barrels, cut them how you want them and screw them on a 870 in 2 min.
This one is not a SBS but i needed a breakdown "truck gun". Really awesome to have a 12g pump that fits in a tool bag. I am sure someone will be made that i "butchered" this thing. But it was a $99 shotgun. A old Stevens take down. Just cut it with a saw and cleaned it up with a file. Shortened the LOP. Installed a bead sight. But you could do the same thing as a SBS if you wanted. But know that the cut down barrels dont always pattern as nice. But sometimes they do.
This is a crappy picture before i finished fitting the bead sight and the recoil plate. But both pieces were cut to be the same size and it packed into a small tool bag in my truck when done.
My brother
bought this one for $130. Again sorry to all the old shotgun guys. But i love takedown guns to travel with and the 28" barrel just does not work for me.