Savage, Marlin and CZ make .17 HMR rifles. Don't know if they sell barreled actions, etc. You'd have to contact them to find out. Competition shooters have actions rebarreled, and would know where to get parts. I and a friend just got done building me a custom Ruger 10-22; Boyd's stock, ER Shaw barrel, and all other parts from Tactical Innovations. (The only thing that says "Ruger" is the magazine.)

Brownell's has gun parts. Check the ads in the gun/shooting magazines. They say you can find anything on the internet...