Thanks Marrakai

and you bet that both barrel system will be disabled.

Even as a shot gun with 2x 3 1/2 inch 2oz loads that aproximates the old 4 to the pound rifles of the 1800's and I read they were most unplesent (worse perhaps with tubes, this gun only weighs about 9lb)

This is a current action I will be using, it doesent have a third fastner but it is massivly built and I figure that if it was built for double discharge then the design criteria with 12 guage is a total of 24,300 lb approx breach thrust one hell of a lot more than 1 .450No.2. (about 6,300lb)

I know some people do not care for us home builders of doubles but could you or some other kind soul give me the outside diamiter at the muzzle of a .450 barrel and also at the 1/2 way point so that I may get the profiles correct.

With regards to the loads, thanks very much, I dont like the idea of fillers and I am please to learn that you are using the same powders that A square tested. It appeared from their data that the tests were very through and I wondered about the RL15 route.

With thanks and best regards