Some paintball players engage in a very dangerous practice of using oil or other petroleum based product as a lubricant and sometimes as a cleaner around their compressed air systems. Another reason paintball players use oil is as a stop-gap measure thinking it is the correct way to fix a damaged or worn nipple seal. Granted it usually works great as a temporary fix until you can get a new seal but the hazards aren't worth it.

The residue left behind by the product can ignite without warning and worse, depending on the chemical make up of the oil you used, the initial fire is sometimes colorless and odorless and then the actual flames will appear. When exposed to compressed air, flammable liquids can become even more flammable and the heat generated from the compressor can actually heat up to the flash point of most petroleum-based oils.

If you want to use oil on your paintball gun, use one made specifically for use around guns that use compressed air. These type of oils are synthetically made and not petroleum based so the risk of turning your paintball gun into an unintended blowtorch are marginal. Synthetic oils also resist freezing and if used correctly will extend the life of the working parts of your marker by keeping everything moving smoothly.

If you see someone using petroleum based oil on their paintball gun, make sure they know the risks and steer them in the right direction. People can use oil based products on their paintball guns for some time without incident, but eventually the residue will build up and ignite. In fact keep an extra bottle of marker oil in your field kit, you may save someone's life!