[Autumn Daze]

The way I understand it Bill is that around 1874 the square bolt was eliminated and the soldered in bolt with the 12 1/2 degree angle came into use. Therefore no hammerless guns had a square bolt. The soldered in bolt plate carried over into the hammergun era but in 1905 King patented the pinned in bolt plate to speed fitting in final assembly and also to be able to harden the insert. Prior to that with the bolt plate soldered in final fitting was difficult because the bolt plate was already hardened. So to me it would make sense that final fitting was mostly done on the bolt rather than the hardened plate. After final fitting the bolt could easily be hardened. The soldered in bolt plate was installed using soft solder so as not to heat up the barrel assembly to a point that the brazing of the lug would be affected. the last variation the bolt plate with the steps on each side further sped up final fitting because of the reduced area that had to be fitted.