Evans9951: My newish XR-100 in 22-250 likes a stout (but not over maximum!) load of Varget powder behind a 52 gr. Berger bullet!
I am also using Winchester brass and Federal 210M (match) primers.
The last two groups (5 shots at 100 yards) my XR-100 made measured .434" (light wind conditions and 32 degrees) and on a previous day (when it was 14 degrees and calm wind) the group measured .397".
I have only tried two loads in this new XR-100 to date.
I have been using it on Colony Varmints and it sure performs well there.
I may do some more load testing this coming winter but so far I am happy with the terminal results with the Berger 52's on all kinds of Varmints.
The one bullet I want to try this winter is the Nosler 55 gr. Ballistic Tip.
I have a Leupold 6.5x20 variable scope on this Rifle and its all factory stock.
Best of luck with your new XR-100 and be sure to let us know how it's coming along.
Hold into the wind
VarmintGuy