Originally Posted by
ToddG
Grease tends to trap particulate/debris far more than oil. Putting grease on the rails means that a lot of gun shot residue from the chamber/breechface area is going to get blown into the rails and then distributed through the grease over time. The result is that the lubrication properties disappear sooner plus you've created a slightly abrasive compound that is rubbing along the rails every time the gun is fired. If you're in dusty or sandy environments, the problem is multiplied manifold.