I have a custom Ruger #1, made for auction to benefit the ISDF, in 1981. This project was sponsored by Guns Magazine, for their 25th anniversary. Anyway, I made a bid for it, and won. It is chambered for something called '7mm RCBS'. When I contacted RCBS for die information, they told me they knew nothing about it, thought it probably was close to a .280 Improved, suggested I cast the chamber and send it to them. I have had this gun for 20 years, and now I would like to shoot it. I don't want to fuss with an obscure wildcat, and wonder if I could have it rechambered for 7 MM Rem. Mag. Barrel length is 24". I live here in the Denver area- any thoughts on who might be able to do this job?