Before finding LRH.com I would have suggested 'go for the one holer.'
I suffer from major "tinkeritus" and have worn out perfectly good barrels playing around.
At this point in a long life I'd say stick with that load, don't mess with it at all!!
The math says that you are, with that group as an example, hitting within 0.35" of POA at 200 yards or 0.175 MOA. Figure how far that will make you rifle effective. It's a right fur piece!!!
This is where I would work up the drop chart for that load then shot in cold bore every once in awhile and go from there.
What are the details of this rig that is being so accurate?