A 1913 Lefever Arms Co catalog atates that all 12ga guns unless otherwise ordered will be shipped with 2 3/4" chambers. No length is specified for the other gauges.
I have a fairly late (likely around 1910-12) 16ga H grade LAC gun in which the chmbers measure 3". RE-Cut??. But at what point in time would there have been more lilelyhood of someone wanting a 16 with 3" chambers than when it was made. I seem to recall that many of the "Optional" lengths of hulls were taken off the market around WWI time.
