Thank you very much indeed, Dig. A wonderful description and most valuable learning, for me also.

I've often thought that CAD/CAM software could be used to build an almost three dimensional picture of the lock and it's inter-relation with the rest of the mechanism of the gun. With colour coding it would be easier to understand than the usual two-dimensional diagrams and photos we are used to. I presume it would then be an easy step to run it through video, showing all the works in action as it is loaded, closed, fired, opened and ejected.

Anyone ever seen such a video?

Tim