To be more precise, Kimber makes the McCormick, Wilson (current), and Nowlin frames. Kimber machines them from forgings produced by one of Smith & Wesson's side operations.
Earlier Wilson frames were made by Caspian. I understand that Caspian's wide-body frame is cast by Ruger's Pine Tree division. Whether this is also true of their single-stack frames is not known.
The forged frames used by Rock River and Les Baer reportedly come from a single source.
Entreprise's source for their frame castings is not known to me.
[This message has been edited by Daniel Watters (edited September 13, 1999).]