By Ruger Varmiter I don't know if you mean a Number 1 or the M77 Varmiter. If it is a M77, unless things have changed
lately I believe this action is still a 300 Win. Mag. length
instead of a 375 H&H length that you would need for a .257
STW unless you want it to be a single shot!
You will not make peace with the Blue Coats, you are free to go.