The Handloaders Manual of Cartridge Conversions by John J. Donnelly lists the .280 DuBiel as having a case capacity in cc's of 5.55 and 85.75 grains of water. The only load listed is 57 grains of 4064 with a 150 grain bullet for a velocity of 3300 fps. The source for the load is listed as "DuBiel".
The case is described as being formed from the .300 H&H Magnum cartridge case, which is listed as having a capacity of 5.755 cc's or 88.82 grains of water.
There is no reference to the .280 OKH. The .285 OKH is described as virtually identical to the .280 Remington.
Keith's book "Hell, I Was There", has several photos of Keith's .280 Dubiel with an external adjustment target scope mounted on it, evidently the 8X Lyman Targetspot mentioned in his other book.
