My unit (USN SEAL element) was deployed to a very active combat area where we encountered frequent contacts with the enemy. When we were engaged, we returned fire using our assigned FN SCAR “heavy” rifles (Mk-17). During these engagements, we encountered a too common malfunction which prevented semi-auto firing and we would have to manually cycle the bolt in between successful shots. We tried cleaning with our petroleum CLP, but this did not eliminate the malfunctions. An operator in our unit recommended we try FrogLube. We started by applying some lube to the rails of the SCARs. Immediately after we began using the FrogLube, the malfunctions disappeared & the guns just ran without a problem. I strongly recommend switching to FrogLube as the only weapons care product for combat units.