Posted by Byron Whitlock on February 19, 2022, 5:30 pm, in reply to "Re: 2 3/4” Chambers"
The original bore diameter of the LC Smith 16ga guns was .650 up until about 1936 when they listed it as 2 3/4 in chambers and .662 bore. The chambers of my 1924 Ideal model measured as 25/8 by my gunsmith and I trimmed all my empty hulls to that.