Do you have a pet .340wby load you'd like to share? also if there's a certain OAL?You are right about factory ammo (especially Wby brand), it really puts a hurt on the wallet.
I have found that it takes a little more tinkering, especially seating depth, loading for Wby rifles. Took me quite a bit longer to find a good shooting load for my .257 & .300. The Wby rifles have a lot of freebore. Once I got the mix right, they are great shooters.