I once ran across a description of a revolver or carbine cartridge from the tail end of the BP era called, I believe, the .380 Rook. . . or .380 something. Anyway, it used a .375-.380 dia inside-lubricated boolit enclosed in the case, rather than a heel design with rim dimensions almost identical to the .38 Special/.41 Colt and was available until about WW1. I'm hoping to get case/chamber dimensions for use in a cartridge conversion of a Remington Beal repro, since the size of the cylinder would provide plenty of chamber wall thickness. The popular method with cartridge conversions seems to be to use .38 S&W cases with a heel boolit or re-barrel to .357 groove dimension and shoot .38 Specials. I'd like to keep it the "proper" caliber, but with the convenience of inside-lubed ammo. Cases could be made from plentiful .38 Sp. or .357 Mag, expanded and fireformed, which sounds fairly easy. I couldn't find it in Cartridges of the World or in Cartridge Conversions or even on the 'net, so I'm running out of places. Anybody got any info or know where I might look?