I feel I have a pretty good input on this one.
I have owned, shot, and modified this rife for over four years now, and put several thousands of rounds downrange, from point blank, to 1760 yards, and just about everything in between, including moving targets at 600 meters, and rapid fire at 1000.
So the long story short...
The action is a bit small for the cartridge. Remington stretched the design of the action to fit this big cartridge in. The general industry standard for .338 bolt heads seems to be .750", but with Remingtons bolt head, it is the standard Remington magnum bolt face of .700", and since the .338 Lapua uses a Rigby .585″ bolt face, it leaves very little material around the outside of the bolt. That said, I have run very hot loads through this gun over my load testing period, and never had anything worse than a sticky bolt and extractor marks. In fact, I have never seen nor even heard of any catastrophic failure of the Remington 700 MLR, ever. This is not to say it has never happened, but if it has, people hushed it up.
The rifle as it comes from the factory is a good, usable rifle. Make sure you loctite your scope base down, I found in the first years that under heavy recoil loads they had a tendency to become loose.
The trigger is a good adjustable trigger, not timney or Jewell quality, but I still run it after all these years, so that attests to how nice you can tune it.
Fit and finish was what I expected from any Remington law enforcement product, good machining, no tool marks, finish was close to flawless other than minor areas that are not visible unless rifle is taken apart.
Limp extraction with the M16 style ejector is present, if you do not pull the bolt back firmly the empty brass will not clear the action. This is a simple fix, either cycle the action firmly, or install a stronger ejector spring. I never replaced mine, I just pretend I am not a girl scout when cycling the action.
Accuracy was surprisingly good on my rifle, tends to be right around or below the MOA mark, but that MOA stays consistent out to a longggggg way away... weather conditions depending of course. If you can hold MOA, that is good enough to hit most targets a long way away the vast majority of the time.
Upgrades I did to the rifle?
-Installed a built in adjustable cheek riser.
-Action bedded
-Muzzle brake removed and replaced with an APA Fat bastard. (Factory brake is utter cow chit... you can't fire heavy loads prone without getting sore after a few rounds, and it kicks up so much dirt from the ground that your eyes are left stinging and watering after every shot. Do this mod first)
-Purchased spare magazine (Hard to find, they run around $120.00)
-Installed badger bolt knob. Makes the rifle much easier to run, a worthwhile upgrade.
-Cheek riser bag. I shoot all year, and touching a cold riflestock at -35c is not my idea of a fun day, so a neoprene and fabric stock back make winter shooting comfortable, and also hold a few spare tools and ammo.
-SAP two round velcro holder. Stick it on the side of your stock just in front of the action, and have two rounds ready for immediate reload. Great product.
Long story short, I want to keep this rifle forever. The biggest reason I am going the custom build route is because I am a hopeless tinkerer and I like making new things, but in the end, the MLR has done just about everything I have asked of it, and even with all the money into gunsmithing, I am still cheaper by a large margin than a custom build, and the finished product is exactly what I had wanted.
In fact, I had it out just on Sunday, was making hits at 1300 meters in 30-40kph wind gusts, on small faraway steel gongs. Too much fun.
Depending on your purpose, the gun can be an excellent companion, but be prepared to put some legwork into making it that way.
Feel free to ask any other questions you have, and I'll do my best to answer them.
Cheers.