I had a Ruger #1 with a bull barrel chambered in 6mm REM and it was one of the best, and favorite, guns I've owned. My oldest son grew fond of it, and I gave it to him a few years ago.
It's a very accurate cartridge, and I bought the gun because I really wanted to try the cartridge out. I shot only factory ammo out of it, but it was just a sweet shooting gun. I had a couple of .243 WIN guns, and the 6mm shot a little flatter and had more punch downrange.
My fondest memory of that gun was shooting a jackrabbit that was running away from me, at around 125 yards with it. Set the crosshairs on the tips of his ears when his head was down and pulled the trigger, and when he came back up on the next stride, it took his ears and the top of his skull off. I was so dumbfounded that it actually worked, all I could do was laugh until my sides hurt.