Posted by David Williamson on April 6, 2018, 6:47 am, in reply to "Re: blueing"
Dave the chambers in all gauges were .014 taper in 2 3/4". The forcing cone on all were a taper of 1 7/8" in 12 1/2". The 12 gauge was always 2 3/4" chambers and the 10 gauge was 2 7/8", but there are exceptions and those are usually noted on the barrels water table. The 20 gauge chambers were 2 1/2" until the mid 1930's but the 16 gauge didn't change until late 1939 or early 1940's. I have a 1939 16 gauge that still has 2 9/16" chambers. The bores on the early 16 gauges were .650 and this changed sometime in the 1930's to .660-.662.