Not saying that the groups you fired aren't good,just that you haven't duplicated the 3/4" group at 200 yards that you claimed.Lets see what your groups look like after the 2000 rounds that weatherby claims the barrel will hold it's accuracy for.I did briefly own a mark V in 30-378,but after being offered a substancial profit for the gun before I even fired it,I sold it and used the money to build my first 300 ultra mag.I felt that the extra cost and even shorter barrel life was not worth the small gain in velocity over the 300ultramag.Below are some 100 yardgroups fired with that 300 ultramag.

http://i34.photobucket.com/albums/d128/stubblejumper11/300ultramaggroups.jpg