Ed,

Finally found your post check out my post under double rifles for the book on rebounding locks for side hammer guns.

As far as actions go I think the easiest to build would be something on the order of a New England Firearms or H&R single shot shotgun type. This would be similar to what Stanley carried when he was looking for Livingston. Or possibly up scaling a sharps 1876 action, however this would be a black powder only situation as far as preassures go.

Alittle more study also answered a question for me when we spoke and you mentioned that you book showed the 4 bore at a 4" case length whereas John Millar had made his a 41/4" case length because his was considered a nitro load rather than a standard. (man this old timers not standardizing things really make it tough to come up with some real difinative answers and solutions.

So I guess my thought would be to go with the .962 bore diameter with a 41/4" case length if it is possible to get that out of the 20mm brass that we talked about.

The other reason I favor this is I will probably use cast lead bullets since I'm looking at a double and they don't particularly like mono metals and I don't know of anyone building a lead core FMJ in this size.

As for bob building barrels he is still looking for one motor that has reverse. we are also pricing what the gun drills and reamers will cost in this diameter. (not cheap I can guarantee)

Anyway as it progresses it answers some questions and brings up others.

Gregg