Red Label 12ga 2 3/4 only chamber

[trapperon]

Ran across an early 12ga fixed choke 26 inch stainless Red Label. Kind of unique as it was stamped on the breech 2 3/4 chambers.
Also had a middle rib sight bead. I know later 12's had 3 inch chambers.
Any info out there on 2 3/4 only 12's or if some slipped out of the factory with a middle bead? I only remember the 30 inch sporting clays models having that mid bead.......and never had seen a 2 3/4 only model!

 

[JSB30]

I had one, would not eject one barrel and Ruger said they do not repair them.