Vahunter,
Wilson, like some other barrel manufacturers, has produced different grades of barrels. Those used in Cooper rifles are indeed very good.
Ruger used the Wilson barrels before they made their own and I think during a period when Wilson had a number of military contracts, possibly too many, that Rugers got a reputation for hit or miss accuracy. Since then Wilson has re-tooled to CNC machinery and is capable of making very fine barrels. Not sure when this took place, possibly late 1990s? Sometime in this same time frame Ruger started producing their own barrels too.
Lothar Walthars are very good and between them and SAKO account for a number of European factory suppliers. They are also a harder barrel like the SAKO.
Weatherby barrels are nothing to be ashamed of, they have had multiple producers but seem to maintain quality, They have been made in California, Germany, Japan, Maine by SACO and now ETEK in Minnesota. Probably others I left off, maybe a Weatherby historian will fill in the gaps?.
