Anybody know how close a Shilen #4 barrel is to the Ruger No. 1B contour? Measurements they provide on their site for the Magnum sporter #4 look awful close to what I dial up on my 1B. Not that the sight mount would fit exactly, it just doesn't look like they produce a direct replacement barrel contour.

Not sure about Shilen, but Lilja will match the profile. I've had several No. 1s rebarreled and the smith who does it for me sends the donor rifle barrel to Lilja to match the contour. Two 6.5-06, 338-06AI, 358 Win, and 35 Whelen so far and all shoot great.