Irish,
I have both .30/378 & .338/378 Weatherby in Accumarks, they are both a lot of fun to shoot and load shells for. They are both a challenge to work up good loads for. If you are new to reloading, I would not recommend either for a first cardridge to start loading to save money. I have reloaded for about 35 years and reload about 70 different calibers (all mine). Although, if you have a good deal of patience then I would say go ahead. You would not be happy with the groups with the factory ammo. The best groups that I have every seen it produce is 1.15 to 1.20 inches. With both of mine after about 10 different loads and several different lenghts (COL), I struck upon the sweet spot of each of these rifles. With proper loads either will shoot better than 1/2 inch groups. I would recommend the Accumark if the cost is not a major factor and if you want a really fine rifle. I have owned and hunted with Weatherbys for over 30 years. I collect West German Weatherbys, but I do have 9 or 10 of the Accumarks and one Japanese MKV in .240 Weatherby. In closing, I will say it is a pleasure to hunt with a Weatherby or any other firearm, so treat yourself to a Weatherby!
Good Shooting!
Marcus.