Anyone have any favorite .340 Weatherby Mag loads? I'm looking to use 250gr Hornady RN bullets. Stocked on Weatherby brass and 300Wby brass I'm necking up to .338 with an expander. CCI250mag primers. Powder can be acquired if needed. I'm not looking to blow up this old rifle either.

Here is a list I used in my .340 Mark V Weatherby. Rel 22 is a very good fit as is H 4831. I would also recommend the newer Rel 23 and R26 if starting fresh.
WMR was very good but no longer made and is supposed to be temperature sensitive, though there was no such thing in Oz where hunting temps were usually between 40-70 F.

250 gn Hornady
86gn Rel 19 2861
87gn Rel 19 2903
88gn Rel 22 2917 4726
88gn H 4831 2839 Original Surplus
89gn H 4831 2870 4574 MOA 3 shots
88gn WMR 2910

250 gn Partition
88gn Rel 22 2921 4738
89gn H 4831 2895 4658 MOA Best Accuracy
89gn WMR 2927 4756

250 gn Swift Sirocco
88gn WMR 2908

250 gn Grand Slam
88gn Rel 22 2902 4678
88gn WMR 3.602" 2889 4634

250 gn Woodleigh
88gn WMR 3.553" 2852
89gn WMR 2925 .7 MOA load
90gn WMR 2941 4803
87gn Rel 22 2907 4692 Best load this bullet
88gn Rel 22 3.659" 3005 5014

I duplicated factory velocity but got a little better accuracy with IMR7828 @ 92 grains using the Partition 250. The velocity averaged 3,025 feet per second.