Yeah, I still have two or three unused boxes of the Bertram .400/.360 Purdey, less a few rounds that I pulled the rims off of. The cases of the .400/.350 and the .400/.360 Purdey are supposed to be identical, but they're not as made by Bertram. The base diameter of the .400/.360 stuff is grossly oversized and will not work, but the .400/.350 Bertram is correct and works fine in .400/.360 Purdey rifles. Doesn't last long though.

Horneber makes .400/.360 Purdey brass, or used to. I have some of it, but don't use it. Too easy to make it out of RWS 9.3 and you can't kill that stuff. It lasts forever.

Yes, the .400/.360 Westley Richards Rimless is merely the flanged round with the rim milled off and an extractor groove cut. I limited my comments to the flanged rounds.
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