Gunsmithing:
Gun Oil, Crud and Parts
A selection of different weight oils from Wilson Combat, which are blended for frequent to heavy use of firearms.
There will be oil, but which one? Okay, I’m not a chemist or a petroleum engineer; I’m a gun mechanic. Oil is essential to any mechanism, but the wrong oil can “gum up the works” for sure. I get a lot of calls for servicing a pistol that does not function correctly. Many times, it’s oil-related. Too heavy an oil is actually worse than no oil at all. The latest pistol I had in was a European target pistol, a Pardini SP-22. The owner had taken a few years off from competitive shooting and now wanted to get back in the game. The trigger in his pistol would not function. On inspection, I found that all the oil had dried out on the sear pin as well as the hammer pin, preventing free parts movement. I had to soak the internals for two days in mineral spirits to free them.
The oil he was using was good for frequent shooting but not good for long-term storage; it was too thick and dried out. Firearms are complex mechanisms with many interconnected parts. Those parts are usually close tolerance fit and require only a light coating of oil.
The late Jerry Keefer and I used to talk about this a bit. There is so much unburned powder and priming compound during shooting that it actually can foul some internal mechanisms; add too heavy an oil, and you get a gritty mud-like substance in the mechanism. Grease is a no-go for most guns.
So, what oil is best? I recommend a light oil if you are shooting frequently; you might need to oil more often, but it does not dry out and, during cleaning, makes it easier to flush grit and grime away. After every shooting session, I wipe down my firearms with a slightly heavier oil on the exterior surfaces to prevent rust. For long-term storage, I might go even heavier, but knowing that a thorough cleaning is required before shooting. I use a spray-on cosmoline product.
What oils are best? I have all sorts — too many to list. But I like to choose my oil by a simple method; I want my shooting oil to be more like water than honey. That said, I don’t think one oil does it all. Wilson Combat has come out with a good kit that offers four oils in a variety of weights or viscosities to cover all aspects of lubrication and protection. Each one comes with recommendations for when and how to use it. This is the right approach in my experience; all four cover most conditions.
Unburnt powder and thick oil form mud sludge in a 1911 pistol, making function less reliable.
Cleaning The Crud
Now that we have a handle on oil, how do I clean the mechanism?
In my shop, I use a parts cleaning tank that holds a gallon of cleaner and has a spray pump; there’s a shelf with drain holes that keeps the parts from the bottom of the tank. In my tank, I use mineral spirits. Mineral spirits do a great job removing oil and gunk, and it doesn’t dry the parts of all the oil like a “brake cleaner” or acetone. Spirits will not harm bluing or plastic. You do need to remove the grips and optics. Old toothbrushes are great for getting into small areas under the slide and frame. After cleaning, I blow the parts dry with compressed air. If you don’t have room for a parts cleaner, you can use a surplus ammo can or a gallon paint can from the big box store to air-tight seal the spirits between uses.
Hand-written “recipe” cards for custom pistol work detailing
the turning speeds and feed rates of machining and listing
specific measurements used in the process.
Recipe For Success
Recently I had a Pennsylvania Gunsmith School student reach out to me about how to keep track of “The Numbers.” By this, he meant all the numbers related to machine work on guns. It is a great question. It’s impossible to remember everything, particularly when you might do it once a year.
I have kept a three-ring binder full of articles and instructions from other smiths and manufacturers for parts installation and machining. The things I learn along the way for myself I keep in a “recipe” box. These are index cards with all the details of a custom process: setup, speeds and feeds for the mill or lathe and the numbers for the digital readouts on machines. Most custom smithing is just that: manual machine work, one of a kind. I might install one or two Smith & Wesson revolver sights on a 1911 in a year. I just can’t remember all the fine details of that complex install. The small index cards are great since I can have them right next to the work. I can also make additions or corrections to the card.
