I am in the final stages of deciding on a custom built rifle. I am interested in the .338-378 Weatherby Mag and a couple of the other big .338 calibers. I plan to use it for hunting here in North America and then in Africa (hopefully some day) and for long range precision shooting. What I am wondering is what receiver can I use, other than the obvious Weatherby receiver, to build this custom rifle from? Any comments would be most appreciated.