Smyth Busters: Can Over-Lubrication Cause an AR-15 To Malfunction?
This video from Brownells Gun Techs Steve and Caleb investigates the myth of whether over-lubricating an AR-15 can cause malfunctions. They explain that while attracting dust is unlikely to be a major issue, excess lubricant can lead to "excess head thrust" by increasing bolt velocity, especially in over-gassed rifles. They also note that excess oil can burn off into carbon fouling. For other firearm types, too much lubricant can actually slow down necessary parts. The video concludes that over-lubrication is indeed a real issue that can cause malfunctions, and that under-lubrication is generally more damaging in the long run. The best approach is to use just enough lubricant where needed.








