If you haven't had any success yet, call Wild West Guns in Anchorage, Alaska. They're the only authorized Remington service center in Alaska, and they are certainly one of the top gunsmithing operations in the United States. They will do it for you, they quoted me at least $800 for rechambering an '06 7600 for 35 Whelen, said it's NOT a simple rechambering. Obviously, you don't know me from Adam, but you'll just have to take my word for it: these guys can do the job and are second to none. Period. Do your biz by phone and you won't be disappointed.