SP-10, I have to slightly wonder if you ever tried hanging that "scope light" from the barrel, because once you do, you won't go back.
Tommy: I go solo almost always because no one will go miles back into 20-degree weather on foot. I carry my own 17-lb battery, the Nightforce (Lightforce) light. Many times I had it mounted to the scope and it was more cumbersome and harder to mount, etc. A barrel can simply take more pressure and abuse and not be hurt than a scope. As far as the "barrel getting awfully heavy," SP, well, it doesn't. I'm used to bull barrels so a tapered barrel with a relatively light light is nothing. It acdtually holds you more steady on aiming, just like a bull barrel.
Remember, with a Lightforce, it's just the light, not the battery, that is attached to the gun. It's just so much more rugged to mount the light below the barrel than on the scope.