I'm surprised that you have seen problems with WR. My plain old T model 318 is absolutely reliable. I'd wonder about soft (?over annealed) cases, too hot loads or dirty, corroded or strangely shaped chambers.

I had a Brno returned from a gunsmith who had it for one reason or other, with a note that it failed to extract or eject the top barrel (375 H&H Belted). It was fine before he got his hands on it. Before taking it out I gave it a good clean and lube and ran a mop coated with jewelers rouge into the chamber using a dremel tool. I just got back from shooting it (50+ rounds) and had no problems.

mike