Gamemaster Sling Location

Alright guys...
I have an old but clean Remington Gamemaster 760. I have a good load developed, and it shoots with the best of them. Am I doing any damage by using a sling that is on the forend cap? My friend has his sling attached to the barrel of his 7600. It looks like the famous Benoit Brothers use both. Does the barrel sling affect accuracy?
So, which is lesser of two evils?