Since I'm so new at this I hope you guys don't just shake your heads but I do have questions. First and foremost I just finished shooting and there is some pressure left in the rifle tank. Is it best to empty it completely or refill it while it still has some pressure in it. Not sure if the compressor will realize the psi already in the rifle. The rifle has a pressure regulator and guage built in. The compressor has an automatic shut off when desired pressure is reached. I appreciate all replies.