45 North,
Just out of couriosity, how do you know that the Nikon Monarch can withstand .375 recoil levels? Don't get me wrong, I own SEVERAL Nikon Monarchs, and they have performed flawlessly for me on a variety of cartridges, but I have never mounted one on a .375, so I was just curious about that. Have you ever mounted a monarch on a .375? If yes, for how long? How many shots?
On my .375 I have an Elite 3200 1.5x-4.5x-32mm. I'm not sure what the parallax setting is, but I have not had any problems with shots between 50 yards through 100 yards. I haven't taken any shots past 100 yards, so I don't know.
Do you know what the parallax setting is on the Leupold?
Here's a simple thought. Why don't you take the Monarch you are talking about, hold it up, and look through it at various distances before you mount it. As such, you can probably answer your question better than any of us. Am I perhaps oversimplifying things a bit?
Zachary