Robert I don't know that the "magnum" in "3 1/4 inch magnum" should be there. Don't know it shouldn't either.
From Burrard's "The Gun and the Cartridge, Volume III" New York, Charles Scribner's Sons, 1932, page 320 there is a table titled "Table XXIX Proof and Service Charges for Different Gauges". That table gives the charges for a 3" and for a 3-1/4" 12 gauge as 3-3/4 drams of black powder and 1-1/2 ounces of shot. Researcher has posted that longer cartridges used to be about more wadding to cushion the shot, not about more powder and shot.
Robert the minimum wall thickness at the forward/muzzle end of the chambers would be a nice measurement to have.
Could you perhaps posts a picture of the barrel flats?
Maybe someone who actually knows what they are talking about will pipe in on this but at one time bore diameter was measured by the largest diameter of brass slug would drop through to about mid-barrel.
I would be suspicious of the wall thicknesses where the bore diameter measures .770" Can your friend get several wall measurements in that area?
The gun still has possibilities even though it appears it is out of proof. In this case my worry would be the wall thickness at the forward/muzzle end of the chambers right before the forcing cones and the minimum wall thickness at the .770" bore diameter areas.
I repeat, a picture of the barrel flats would be very helpful.
Best,
Mike
Last edited by AmarilloMike; 09/20/12 07:52 PM.
