I just think they don't want to do it lol. There's tons of rebarrels with cases that size and much larger on a No. 1 action.
Just a polite way of saying they don't want to do the work. They could of at least said so.
I'm in the process of finishing a #1 in 50/90 Sharps and I mean to use it solely with smokeless powder loads and probably mostly with cast lead bullets for hunting bear, moose and elk in heavy cover. A good friend of mine is a collector of #1's and has both African models in 458 Win and 375 H&H, I see no reason you couldn't have a competent gunsmith to build you a custom #1 in 460 or 378 Weatherby, I talked with a fellow at a gun show last year that claimed he had one chambered in 470 Nitro Express but couldn't remember who the smith was that did it for him....Good luck
I am an "addict" for big bores, grew up reading Hemingway, Roark and Roosevelt about hunting in Africa, well, never made it to the Great Continent but never lost my love of the rifles that were used there. I've had both 378 and 460 Weatherby's in the past years and they both "delivered" on the receiving end as well as the out going end, I found the 378 had a sharper jab than the 460 but the 460 had more push, after I installed muzzle breaks on both of them they became a lot more tolerable to shoot off the bench, of the two I liked the 460 best, it was a joy to shoot with light loads and cast lead bullets and was more accurate than the 378 with the same. Velocity's would range from 1500-2000 fps depending on the loads with 420-550g bullets.
A lot of people will shoot a .460 but not a .378. I had a .460 for a short time and messed around with it but never hunted with it. To me the .378 has awesome ballistics and would be more practical if there is such a thing with a rifle that hot. But yeah a 300gr bullet at 3,000 fps is pretty awesome and would make a pretty good elk round. I've always heard the .378's recoil is terrible even with a brake so I never bought one, I ran into a helluva deal on one a few years back at a Tulsa gunshow for $750 but the stock was cracked in the pistol grip area so I put it back down on the table. Probably should've bought it but that scared me away.
