You must really have a problem out there with charging bean bears, since you keep mentioning 50 yard shots.

Maybe I should come out there and bring my 338 win mag and my 375 H&H to help you eradicate the little buggers!
Don't tease Hammer! He has seen attacks and gnawings on the American Great Plains that no man should have to see.

I know for myself, that ever since I witnessed the fatal gnawing of Scratch McGee, I often wake up screaming, in the middle of the night, soaked in cold sweat.

In regards to the 240 WBY, if want it, if the air will be cleaner, the sun will shine brighter and you will be happier go for it.

If you are still open to suggestion, go to reloadersnest.com and compare the 250 Ackley Improved to your Wby. With 80 and 100 gr. bullets, you get the same velocity with 9-10gr. less powder. Just something to think about.