I built a 50 on a Barnard action for a fellow, the tolerances of the action were good, these actions seem almost over built, and thats a good thing.
The only 2 things I was not thrilled with is the lacking of a recoil lug, which I solved by making 1 and that to remove a live round from the chamber 1 must remove the bolt. Which is not a big issue if you don't mind dropping the cheekrest to remove the bolt each time.
Every normal style bolt action like the Barnard, McBros, RPA share 1 thing in common, the actions are all 12" or longer in length, which makes the rifles very long when you use a 30 plus inch long barrel.
Every action has pros and cons, the singleshots I build have 4" long actions, so rifles can be shorter. The downside is that they are slower to load as the cartridge must be set into the bolt similar to a shell holder in a reloading press.
The Nemesis rifles I am bringing in are repeaters and have folding stocks to keep the rifle compact for transit. I am sure that once they land here, we will discover like all rifles there are pros and cons as well.
The best advice I can give anyone looking into a 50 is to make sure you can get parts and service in country.