I bought this 2nd hand .257 Wby mag a couple of weeks ago. It came with a Zeiss 2.5-10x44 scope. I worked up some loads using the 100grn Barnes TTSX and several different types of powder. And well just about every load I tried shot absolutely terrible! I'm talking 3-4+ inch groups at 100m. With the exception of AR2217 (H1000) which I manage to get one group just on 1.5 inches. To say I was extremely disappointed would be an understatement.
I hadn't cleaned it before going to the range as it looked quite clean. So anyway, I set about to give the barrel a good scrubbing with some Bore Tech copper cleaner. And when that first patch came out it was bright blue and filthy. I ran several soaked patches through it followed by heaps of scrubbing with a nylon brush. I kept on doing that until after almost 50 patches they finally came out with no sign of copper fouling. I then used some more solvent targeting leading and powder contamination. It took quite a few more patches but they then came out nice and clean.
I didn't really like the Ziess scope that was on it, so I put on a Leica ER5 2-12x50 scope in one-piece medium Leupold lightweight rings and bases.
So back out to the range with it and it turned into quite a good shooter. The 1st and 2nd shots would always be touching or close to it but then the 3rd would shift about 1/2-3/4 of an inch of to the side. It would constantly do this. But I was happy with it as those first two shots are the main ones that count.
I was also sick of having a safe that was to overcrowded so I bought a new Spika 33 rifle safe just to put most of my Weatherby rifles in so they wouldn't be touching and getting damaged. I am very happy the way my rifles sit in there now.