I own the MLR in .338LM, and I had the chance at a private shoot to have a good long chat with another gentleman who owned and was shooting his 700 XCR in .338LM.
His basic opinions of the XCR were the exact same as mine to the MLR.
My rifle....
Our rifles tended to shoot just over MOA out of the box with most factory ammo, and can be dropped to a reliable and repeatable 0.75 or 1 MOA with quality handloads.
Both of us intend to have the action bedded, and both of us have purchased replacement muzzle brakes due to the factory brakes kicking up a lot of dirt, small children, and dust. (Both of us happened to separately choose the APA fat bastard)
Neither of us intended to rebarrel until the barrel was shot out, so I can not speak for the rebarreling and truing.
If you go with a large objective lens (ie. 50mm like both of our NF scopes were) on your scope, even with low rings, you will need a cheek riser that raises your cheek by approx. 3/4". The cheek bag style cheek risers only seem to give about 1/4" raise, so you will need to think about a proper solution like a built in cheek piece like the Loggerhead ACP, or a bolt on one like the Karsten Cheek Riser.
With my MLR and 270gr Lost River Ballistic Solid copper bullets, I made a perfect headshot on steel at 900 yards in 4 shots (2 to get on target, 3rd on steel aiming center mass of torso, and a final wind and elevation call to get the headshot), a feat that was almost precisely duplicated later that day by the gentleman with the XCR and hot 300gr SMK handloads, but I didn't get photos of his target.
Here is the hit from my shot, which he duplicated with very close to the same number of shots... My hits are the copper coloured ones.
Conclusions?
The rifles both shoot acceptably well out of the box, quite well with handloads, but can benefit from some tinkering and gunsmithing to improve it further if you are truly very serious about your LR marksmanship.
