My books show the Sherwood with a case length of 1.550. Base diameter (above the rim) is .3201 tapering to .3181 at the neck. .3748 rim dia. So it's in the ball park and the Sherwood is a WR proprietary cartridge fielded to compete with the 310 Cadet. How long after the cast did you take the dimensions? I ask that because a .299 bore dia. and a .300 case dia. only leaves 1/1000th for case wall thickness. That's thin. Too thin. Even considering they made much thinner cases in those days. I haven't done a chamber cast in a long time but I recall that the cast takes and hour or so reach full dimensions.
.300 Rook is:
OAL (loaded is 2.0402
Case length 1.152.
Rim diameter .3748.
Base diameter (above rim) is .3189 tapering to .3181 at the mouth.
Sweet rifle.
Nick T.
