Neat rifle. I forgot to say so before but I was reminded by your thread on the 320 Rook over in the reloading section. The Greenwood book has a good section on cartridges and reloading, if you don't have it it's a nice reference to read about the various designs and speculation of who actually made the actions.

This summer I picked up an H&H Royal that I think was in 300 Rook, still havn't figured out how to take the forend off to confirm, but was relined to 22 Hornet. The relining was well done and the rifle is very accurate, it also saves me trying to make 300 ammo.