This is my rendition of the Galazan BWT gage. I haven't finished the 16-20 ga. side yet. I have made a few modifications to the cone shape. The first one I made would not let the breech end go all the way down to center on the cone. The second one I made was good for 12 ga but not for 10 ga. The diameter of the cone was not big enough to let the 10 ga breech end bottom and center itself and when switching to a 12 ga. the diameter was to big and the 12 ga. barrels would not center without hitting the extension rib. Finally got one to work.
On measuring from the muzzle, meaning breech up and muzzle centered on cone, I still find it hard to believe the top heavy end of a 10 ga does not flex or torque the rod. I came up with the idea of using a 7/8" diameter spirit level and sitting it on the breech end and watching to see the the bubble stays in the same position as the barrel is rotated from top to bottom rib.
I don't have access to a milling machine right now and am using my 20" drill press with an X Y table and it isn't fun trying to mill out the area for the spring loaded brass rod. Also to mill out a piece of 3/4" aluminum to hold the indicator mounting slot in.
Of the ones I have made, the Manson and the horizontal one, this one is the easiest to use, especailly when using a digital indicator, makes taking readings very easy.
