Hate to differ, but my 7 Model 12's, dating from 1921 through 1949, have all been shot a ton, the 3 12's with steel shot for 30 years hand runnin' they are still as smooth and solid as when they came into my hands, and the 3 12's I use with steel shot are all full choked, and there is NO bulging of deformation of the barrel in any way shape or form. I have in the gun cabinet a framed ad from a No.v 1957 Field&Stream magazine- showing a hunter holding a M12 and he's sitting on a huge pile of empty Red Winchester hulls- and a freight care in the background- the ad states: "A Lifetime of Shooting Won't wear out a Model 12-- That, boys and girls, is what Hemingway would have called "The True Gen"-- count on it.. RWTF
