For the most part you don't need to lubricate delrin(It lubes itself). In the event that the delrin becomes dry, NEVER use oil to lubricate your bolt. I suggest a dab of vaseline(as little as possible)should be rubbed over the surface of your delrin bolt. If that doesn't help than I suggest you take it in to have it serviced
. THe vaseline technique has worked for me in the past. I onced tried using oil and my bolt swelled up and absolutely would not fit in the gun.