I"ve always just used WD-40 on the practice and match guns, cause it gets replaced/cleaned off a lot. For duty guns, I degrease them with rubbing alchohol, because oils hurt the car wax that I then put on their exteriors (2 coats) as rust preventative. For the friction areas, I use tiny amounts of LockEase graphite (your hardware store should have it). Graphite will "migrate" and stain clothing if you overdo it. Good guns need very little of this lube, to include AR-15's.