Are you sure that the MR7 had micro groove rifling? I thought that was only a rimfire thing.
My shooting pal has a MR7 in .270, and I'll sure check it out soon. He bought his last year, and with absolutely no mods, it shoots like a laser. It's has wood touching the barrel, and the trigger is heavy, but he's able to shoot under an inch at 100 yards with factory ammo on a regular basis. He's made some long distance kills on deer, so I'd say he's pretty happy with his Marlin. They're just uncommon enough to be rather cheap at gun shows, so he got a good deal on it. I can't see anything that won't hold up on them over time, and, at least his shoots really well, so I'd sure try one if I were so inclined. But, I'm a Ruger and Tikka fan, so I'll pass on them for now.