I am doing this off the top of my head, I am not a mechanical engineer, and I didn't sleep in a Holiday Inn last night. Such things are not unknown, I believe Anschutz sold Hornets and even .222's built on their 54 action, but this project is probably beyond where a home builder would want to go. The Hornet operates at more than twice the pressure level (22RF is higher than most people think) and has a significantly larger case head area which means more back thrust at that higher pressure level. Even if the action lug area is adequate, how about the steel and hardening? My father had a new 52C develop a headspace problem in about 1960 and it had to be sent back to the factory to be repaired.
There is also the liability concern, both legal and moral. In the single shot world I see people all the time using weak actions and saying they know what they are doing and won't overload them. Those people will die someday and who knows if the next owner will be so cautious. We don't have proof houses or requirements in this country, so you can do what you want, but I would leave it a .22RF.
