Microslick is a product originally designed for use on the internal parts of automotive motors, such as piston heads. To call it an advanced dry film lubricant is probably doing it an injustice. It is far more advanced than that. This is the product we use on most of the internal parts of our rifles due to both lubricity and how thinly we can apply it. Microslick is the finish to be using on internal parts of AR15 rifles.