Got some more done on these 

Here is one of my barrels set up on the CNC mill I run at work. 

I machined pockets into the sides for the trunnions to screw into. 

Here is a finished pocket. It was milled on the CNC with a 1.5" endmill. 

This old mill is kind of a "bull in a china store" when it comes to threading. Better do this buy hand;o)

More to come...
Wes