That's going to be tough. However, I'd check with Brassmanbrass.com, they carry a lot of Weatherby once fired brass. I believe they are currently out of just about everything. I suggest giving them a call to see what they have. Good luck.
Here is what I have if you're interested
20 rounds of Weatherby Factory primed brass
20 rounds of Weatherby Factory once fired cleaned brass some i primed and some I didn't .. I don't reload any longer and have more 257 ammo than I will ever use in my lifetime.( Not interested in selling any of that sorry )
$85 shipped to ypur door USPS priority mail.
If you don't want them I will post them for sale.
Greetings all! I've been a hunter for 50 years, but only now planning a trip to Africa. I was fortunate and successfully bid on a couple hunts for plains game in SA later this year and next. Also a rare Native Texas (5th generation) and USMC Vet. Hunt safe y'all!