Boyle Gamble & MacFee

Albert N. Hardin, The American Bayonet 1776/1964

Quite possibly the bayonets were made to suit a number of arms, which is strongly suggested by the number of bore diameters in specimens observed.  

To accommodate the bayonet, the firearm required a bayonet stud.  BG&M chose to produce an adaptor to accompany the bayonet, then to fit permanent studs to a varied lot of firearms.  The bayonet adaptor is a cylinder of cast brass which swells along one sector to permit its passage over the front sight.  About 120 degrees away from this swelling, the bayonet stud member is cast.  It has the basic profile and form of any standard stud except that its center third is cut away in the transverse plane to the depth of the major member.  The stud lock of the bayonet passes through this mortise, rather than along the end of the stud as is the usual practice.  Midway between the sight notch in the adaptor and the stud, there is cast a flat-topped elevation.  A hole is tapped transversely through its center to accept a retaining screw to tighten to the firearms muzzle.  The bores of the adaptor specimens viewed average .922 inch (23.4 mm) in diameter.  

Two markings are found on these devices.  First, a serial number to match that of the bayonet to which it was mated, found on the forward side of the stud.  Second, the manufacturer's stamp located on the ring surface opposite to the screw and adjacent to the stud, consisting of a large "BG&M" / a tiny "RIDHMOND, VA" / a slightly larger "SEP. 2, 1861".