I own and reload for 300WBY and 340WBY. The full length WBY cartridges are too intense for many shooters.
My hunting experience with the 300WBY is only four mule deer, but this chambering is like the fist of God! None of the mulies took a step. I was expecting long range shots, but the longest was a little over 150yds. I recommend a premium bullet, I was using 180gr Triple shock and it did less tissue damage than I expected.
IMO the 300WBY is more suited to long range quartering shots on larger game. You can't anticipate those though.
As to the rifle, the MKV is the state of the art in pushfeed designs, IMO. My 340 was left to me by my late uncle, it's circa 1970 MKV Deluxe, made by Saur and Sons in Germany, and is a work of art. I haven't hunted with it, it sits in my brothers safe in Spokane.
An old timer told me about a gimmick that will allow you to shoot longer at the range. You take a new pair of tube socks and fill one 2/3 full of #8 lead shot and sew it very well with heavy thread, put the other sock over it opposite and sew it very securely. I put it between the butt and my shoulder. This in effect adds 15# to the weight of your rifle, making recoil negligible. I like to test several loads over the chrono and this makes this testing tolerable. The shot sock will effect the length of pull and cheek weld, but it allows me to shoot 30+ rounds at one sitting.
I hope you know that you are now a rifle snob, welcome aboard.