I took measurements on mine some time back but don't think I recorded them. I did post them here to the forum at that time, but don't recall how long ago. I have essentially three sizes of bars. I don't recall if I actually measured the rear of the frame where the stock attaches or not. An XX frame 16 has a slightly narrower bar than non XX frames, don't recall about depth. I have 12 gauge guns from 6 1/2 lb to 8 lbs & they all have the same size bars, firing pin spacing's & breech ball sizes vary of course.
An early 10 gauge 32" 10 lb side pivot lever gun has a larger frame bar than any of the 12's
My xx 16 weighs 6 3/4 lbs. It has thick heavy barrels with matching breech balls. Firing pin spacing is a bit wider than most 16's.
