There has been a fair amount of discussion in the past few days about a “gun oil” that is suspected of being nothing more than repackaged Canola oil:
In response to a Facebook post on this topic I wrote the following comment:
We sometimes grow rapeseed and canola on the farm.
Rapeseed oil is the main component in all the “synthetic” motor oils. It can tolerate higher temperatures than the pumped from the ground. Rapeseed oil is believed to be toxic (not dramatically so, but you shouldn’t cook with it on a regular basis).
The Canola plant and seed look identical to rapeseed but the oil is much lower in erucic acid than the oil from rapeseed. The erucic acid is desired in the lubricating oils.
Canola oil is not going to be as good a high temperature lubricant as rapeseed oil. If you want to use something cheaper than the hyped up gun oils but better than common lubricants then use a Mobil One or some other synthetic motor oil.
There are some severe factual errors in that comment. It was probably 45 years ago Dad had told me Mobile 1 was made of rapeseed oil. Yesterday I discovered that was wrong. I went searching for a web page to show it was true and could not find evidence to support that claim.
I sent an email to my brother Doug asking him what the story was. He wrote back saying he had discovered the error many years ago himself. Dad was not one to exaggerate or make things up and Doug elaborated on how he might have come to this erroneous conclusion.
He elaborated quite a bit but it boiled down to the following (slightly edited to remove names):
I don’t think Dad fabricated the entire rapeseed story. When I first started farming, I sat in several farm meetings where rapeseed and its many industrial uses was discussed. I think much of it came from a certain plant breeder. Dad really liked him and I did too. He seemed like a great guy, but I have heard he was a bit of a visionary/exaggerator. He left in the late 80s and was replaced. The new breeder also seems like a great guy, but I have seen the results for enough years to know that most of his dreams don’t come true. His great plans for various new crops have all fizzled over the years and he really has very little to show for his 25 years of plant breeding.
In answer to your question, I suspect much of the hype about rapeseed came from these two plant breeders and much of it was based on wishful thinking rather than reality. I don’t have any other good explanation.
I did further research and found that while rapeseed oil has been used for lubricating oil for a long, long time it doesn’t have the extraordinary high smoke point that I had been lead to believe. When refined it is higher than many cooking oils but it’s not anything worthy of exception note.
The synthetic oils, like Mobile 1, do tolerate very high temperatures but it isn’t because they have any particular vegetable oil in them. It is because they have very particular, custom built, molecules in them that are temperature tolerant. Conventional oils, and vegetable oils, have a wide variety of molecules in them. Some of the molecules break down at lower temperatures than others. As soon as any component of the oil starts breaking down it changes everything. The viscosity can change, the lubricity can change, and the oil will cease to do its job.
I suspect that high temperature tolerance is important in firearms but I don’t know for certain. It’s not as if the oil is for the chamber and barrel of the gun. It’s for the metal on metal parts of the gun which doesn’t reach chamber and barrel temperatures.