Welcome to the forum. Odd that you inquire as I've just put up my last 3 boxes of ammo for that caliber, on another forums classifieds. The standard twist on the Mk V should be 1 in 10. Here is a location with most of the specs for that caliber.
Welcome to the nuthouse. Cool caliber to be inquiring about.
If you are building/buying a rifle in that caliber, have fun with it.
“There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves.” – Will Rogers
Replies
http://en.wikipedia.org/wiki/.30-378_Weatherby_Magnum
http://www.nosler.com/Reloading-Data/30-378-Weatherby-Magnum-165-Grains.aspx
“When guns are outlawed, only patriots will have guns.”
http://www.weatherby.com/product/rifles/markv/accumark
Welcome to the forum.
Gun control laws make about as much sense as taking ex-lax to cure a cough.
Welcome aboard.
If you are building/buying a rifle in that caliber, have fun with it.
Hunter 1000