I use Mobil 1 synthetic oil 0-40, and Mobile 1 grease mixed at a ratio of 6 to 1. Using a paint paddle with an electric drill, it mixes well enough like an emulsion to keep the qualities of both oil and grease. A quart of oil and a tube of grease will last several lifetimes.
For bigger jobs, it goes into an old-fashioned mustard-ketchup squeezable plastic bottle with a long spout on top, and for most uses a small needle bottle from Brownell's.
I use this mixture on everything from AR15s, to a Garand, to all my pistols and revolvers.
Most of the time after application I use a finger to smear it around on bolts, and a Q-Tip on slides and pistol interiors where friction takes place.
No gumminess, no cast-off - stays put until the next big cleaning using Simple Green Extreme (safe for aluminum) to clean off, then reapply.
Most gun oils and grease are high-priced marketing goods that cost more than a porterhouse steak, but do no better than this concoction.
Spend your money how you wish. But "Magic Super-Duper Gun Oil" is expensive hogwash.