Most mod 12's had 2 3/4" chambers & max barrel lengths of 30 "
The heavy duck generally came with 32" barrels & 3" chambers. Having handled & observed many 12's over the years, I sure there were variations & special order guns, Winchester in those days would accept special request. I would say that over the years, ribs or the lack of, varied. But solid or what was called matted is the one that comes to mind most often when speaking about the special duck. Full or super full, fixed chokes will be the most encountered. !2 ga. of course.
The quality of the M12 goes without question. All solid steel, machined parts. Built in adjustments to compensate for wear. Nearly indestructible. Heavy. Not rated for steel shot.
Have it opened to Modified and happily shoot steel. Or just use one of the other new heavy shot options, which in most cases will be the better choice.
