A while back I helped this guy reblue this shotgun, the guy didn't want to go through a lot of effort, just clean and reblue. It had some awful pitting, some of which was so deep (and on the thin end of the barrel) that I wasn't comfortable removing metal anyway.
Well the rust returned, when you skip a step, sometimes things like this happen.
He brought it back asked if we could convert it to a home defense shotgun, by removing the vent rib, cutting the barrel down, removing what pitting we can, sandblasting the metal and reblue it.
This is what it looked like before we started
We cut the barrel to 20", We wanted to leave a little wiggle room in the event the owner wanted to add a pistol grip later. To properly measure the barrel length, inset the bolt into the locking recess on the barrel, next stick a dowl down the barrel until in rests against the breach face on the bolt. Mark the dowel and then measure the length
After cutting the barrel We removed the vent rib, by prying the rib off of the stanchions, then snapping of the stanchions with a pair of pliers. We then filed the remaining metal.
Here it is after sanding/filing. We will now try sandblasting the barrel and magazine tube with heavy grit abrasive.
I sandblasted them and the magazine tube pitting was deep enough to blow a hole through the metal, I was afraid this would happen. It is a non-critical part and the rest of the metal is solid, so it should be OK
After removal from the bluing tank the parts had a red/orange rusty film, but no worries, this happens some times and is not reflective of what the finish looks like underneath
Here it is assembled, it doesn't look the best, this one might have been a candidate for a paint or Cerakote job (especially considering what the new intended use is).