My daily carry pistol is a Glock, and Glocks are pretty much unique in the firearms world in that they seem to work just as well whether dry or well-lubed. On the other end of that spectrum is the AR-15, which is universally acknowledged to run better "wet."
Over the years I have accumulated a dozen wonder lubes, some of them specifically formulated for the AR-15 platform. Out of curiosity I recently asked a number of shooting acquaintances what they preferred for lubing the AR-15. What I found fascinating was not just the number of home recipes, but how no two answers to my question were identical.
I consider RifleShooter contributor Dave Fortier one of the most knowledgeable tactical rifle guys around, and he told me the best stuff he's found is Joe Bruch's Masters Gun Oil. I first met Joe years ago when he was working as a volunteer range officer. He's one of those quiet, unassuming guys, and you'd never know he's a chemical engineer who has developed his own line of lubes.
Alan Adolphsen is the owner of Teludyne Tech and inventor of the StraightJacket barrel system. Adolphsen is a former competitive rifle shooter as well, and he has two preferred AR lubes, both of them home brewed. The basic recipe consists of 10 parts tool oil to one part Hoppe's No. 9, the only difference is whether you want to add automatic transmission fluid.
How much automatic transmission fluid does he recommend? "Enough to make it good and red," Adolphsen told me.
The "red oil" a lot of gunsmiths talk about is homemade lube that contains automatic transmission fluid, but everyone seems to have his own recipe.
George McCleary is a former Marine sniper and member of the Marine rifle team.
"Back in the day, the red oil we used on the M16s was one quart automatic transmission fluid, one quart HD-30 motor oil, one pint Marvel Mystery oil, one pint STP Oil Treatment and one small bottle of Hoppe's No. 9," McCleary told me. "Mix it in a gallon milk jug. If you had a stencil brush you could apply it on everything inside and out, wipe it down, and the rifles wouldn't rust — even in the Carolina heat and humidity. The guns cleaned easy with any solvent because the carbon wouldn't stick with the Hoppe's in it."
"Today," McCleary explained, "a lot of the training gurus honestly use a light Mobil 1 in a spray bottle."
Gus Norcross is the founder and owner of Angus Arms, former National Guard Marksmanship Training Unit armorer and a state service rifle champion. His red oil mix is similar to McCleary's, except he prefers multiviscosity oil instead of HD-30.
"You want a light oil that won't burn off," Gus told me. "I've also been using Militec for four or five years, and I've had very good luck with it.
As a commander of a Bradley infantry fighting vehicle, Dillard "CJ" Johnson and his crew got involved in a near-nonstop four-day running gun battle in the first days of the Iraq war, for which he was awarded the Silver Star. Johnson did a second tour as a sniper and has been shot and blown up enough times to earn his weight in Purple Hearts.
As commander of the Bradley, he was credited with hundreds of kills just in the first few days of the Iraq war, many of which were made with an M4 carbine. His preferred lube? Simple 15W40. "Ask the Iraqis how well it worked," Johnson remarked.
I found it amusing that all sorts of fluids not designed as gun lubes were being used as such. But think about it — what are motor oil and automatic transmission fluid but lubricants designed for rapidly moving, sometimes very hot, metal parts? Why wouldn't they work well as gun lubes? How many tens or hundreds of millions of dollars have been spent on improving the lubricating properties of motor oils and transmission fluids?
Since I'd never tried "red oil" I mixed up a batch of my own with 10W30 Mobil 1 synthetic oil, automatic transmission fluid and a dash of Hoppe's No. 9. Sometimes you never learn until you do it yourself, and making my own red oil taught me a few things: One, the mix results in a medium-light lube that is thick enough to stay in place but not so thick it gums things up; and, two, cheap spray bottles designed for water will work when filled with oil, but not very well.
Heading out to the range with an AR lubed with red oil will give you dissociative flashbacks if you've ever worked on a car. Normally when I start smelling warm transmission fluid it's time to pull over to the side of the road and pop the hood. I kept pulling my head off the stock and looking around for my old Impala.
In addition to the lube preferences of my expert associates, I know two well-respected firearms instructors. One of them uses basic 3-in-1 oil (what my mother called "sewing machine oil") on student ARs, and the other swears by high-tech Slip 2000EWL. As long as the rifle is well made and maintained, it seems to me that as long as it is lubed, which lube you use seems to be more a matter of personal taste than anything else.