Both CO2 and spring powered air guns do need some maintenance to help ensure a long life. Keeping them clean is a big part of that care, but you do need to be careful about what you are putting in and on your air gun. The valve assemblies in today’s CO2 powered air guns are fitted with silicone seals and O-rings. This is important to note as the use of a conventional oil will cause the seal to deteriorate. One of our techs describes this using the analogy of gasoline and Styrofoam. The silicone/petroleum reaction is similar but much slower.
Read the rest: What Kind of Oil Should I Use? – Umarex USA