Try to find non-flammable lubricants for use in paintguns, and don't smoke while applying oil to, or using your paintgun. This section describes some of the more common plastic and elastomer compounds found in paintball guns. It also contains information about how these materials interact with various lubricants. Silicone is good at resisting acids and will operate over a very wide range of temperatures, however it is not a very good choice for use as seals in paintguns because of its susceptibility to damage from petroleum products. Silicone rubbers tend to absorb silicone fluids, resulting in swelling and softening of the compound.
Nitriles are one of the best choices for use in paintguns.
O-rings with a high nitrile content are good at resisting chemicals and can be designed to endure wide temperature variations. Nitrile o-rings must contain some plasticizers in order for them to function at extreme temperatures. Almost all nitrile o-rings are black in colour. They offer very good performance in abrasive environments, but lack the ability to withstand acids, ketones and chlorinated hydrocarbons. Crazing weakens the polycarbonate and eventually leads to complete failure of the structure.