I don't have a Rem XR-100, but I certainly like Remington 7½ primers in my Winchester casings and a stiff load of H4895 powder with the 39 gr. Sierra BlitzKing bullets. Ruger No. 1 seems to have found a very good load for his rifle. From Sierra's load data, that load 25.2 gr. of H4895 supposedly gives you around 3,400 fps. Is that about the velocity of your load Ruger No. 1?
Currently, I am using quite a bit
HOTTER load than that in my Savage 12VLP. It is over the recommended load in the Sierra load data, so if you intend to use H4895 and try to duplicate my load, start well under my load and work up slowly. Here's a 3-shot group from 100 yards off a concrete bench using a Harris bipod for the front rest and a rabbit-ear bag for the rear rest. When I shoot 5-shot groups, they are usually .500" or so.
You are going to enjoy that Rem XR-100. I have read lots of good reports on them. Post some targets when you get into your load testing phase.