Mag-na-port is, or certainly was, a patented process, and only one company in Canada was licensed to do the work. It was reported that they lost their license because of too many customer complaints regarding the quality of the work that they were doing. For quite a while no one in this country was legally able to do it, although if they called it by a different name perhaps they could get away with it.
As of this moment I believe this company is licensed, and if so the patent holder will probably stand behind the customer.
A word of caution; The story going around ten or fifteen years ago was that it's easy to make a mess of the job, and it could knock a lot of value off a rifle.
Weren't Weatherbys the only rifles Mag-Na-Ported at the factory? They were the only ones I saw and shot anyway, and it worked very well.
Mag-Na-Port Pro-Port Canada
Selkirk, MB
R1A2J7