Huvious,

Perhaps the double rifle action holds it's width from ball/fences forward in order to accommodate a larger diameter hinge pin ???

If the hinge pin is bigger in diameter - in order to withstand increased pressures - and does not go the entire width of the knuckle - to accommodate cocking rods - the knuckle may need to be wider to suit (see I didn't say accommodate again !!!) a longer bigger diameter hinge pin.

It has been stated that shotgun actions don't handle conversion to double rifles due to the increased pressures - but there are many instances of exceptions - and that they might be shallow in the bar, lack reinforcement/width at the elbow of breech face to bar, lack hinge pin diameter, knuckle width, bar length etc,etc, etc.................but where are our "base line" dimensions coming from ????

To add confusion to the mix - if that were necessary at this point - you read of 600s being built on 500 actions, 450/400s being built on 20 guage actions etc in order to get weights down.

I believe alot of these dimensions are arrived at out of fear of actions failing and that some of these double rifles are "overbuilt" out of caution - wisely so - but perhaps, with the improved steels of today, this may not be as necessary as it used to be with "yesterday's" low carbon steels case hardened to add strength.

Bearing in mind I am aware of the necessity of the finished firearm to be of suitable weight to make it shootable given the recoil generated by the cartridge............ and for weight distribution that will make it handle.

I am interested in views................perhaps my thinking is wrong!!!??:?