Here's some stats on castor oil. Which particular stats on the oils that you posted make you believe that any of them are better for gun lubrication than plain old castor oil?
Castor oil
Pour point: -27.4 F
Flash point: +446.0 F
Viscosity at 100 degress Fahrenheit: 259-325 cSt
Viscosity at 130 degrees Fahrenheit: 98-130 cSt
Transient operating range: 473.4 F
Viscosity index: 135
Castor oil is actually an excellent lubricant, which is why it was used so long as the crankcase oil of aircraft engines. With a good additive pack, it would probably work fine as a short-term gun oil. The problem with castor oil though is that it is susceptible to oxidation (
unlike polyalphaolefins in Group IV based synthetic oils), which is why castor oil turns to gum in a relatively short time. Hence castor oil is no longer used as an engine lubricant (or a gun lubricant) even though its lubrication qualities are quite good.
So I'll ask you the same question...which particular stats on Rem Oil (petroleum distillate based) or CLP make them better gun lubricants than a good group IV based PAO synthetic multiviscosity oil in the 0W20 to 5W30 range with a decent additive pack? If you are concerned about the ZDDP content of Mobil 1 EP, Mobil 1 Delvac of the same viscosity would certainly address that particular issue, would it not?
Or to use the flat-tappet-cam analogy mentioned upthread, how long do you think the cam lobes and lifters of a flat-tappet engine would last at high RPM if you completely replaced the oil with CLP or Rem Oil?
The thing is, many (perhaps most) mass-market gun oils are intended to carry out multiple purposes, with corrosion protection as job #1 and lubrication as a distant second. For corrosion protection on the exterior of a firearm, you need a very thin film and/or high solvent concentration, which are great for preserving a gun's exterior finish but which compromise its lubrication qualities to some degree. Hence I think it is beneficial, particularly for semiautos, to use an internal lubricant that is optimized as a lubricant, and use the multipurpose products on the exterior where the primary concern is preventing oxidation and where thicker lubricants would be too messy.
Would you put Mobile 1 in a sewing machine? Would you put 3 in 1 oil in a V8 ?
Mobil 1 is too thick for a sewing machine, but I'd darn sure use some other modern synthetic oil in place of 3 in 1, which in my experience turns to gum over time. And I use Mobil 1 in my car specifically *because* it is a better lubricant than petroleum-distillate-based oils.
There is such a narrow focus with people on what features of a lubricant apply to what uses. Hey, why not use virgin olive oil ?
If virgin olive oil made a better gun lubricant than a Group IV PAO based synthetic with a good additive pack, I'd use it. It doesn't; olive oil doesn't prevent corrosion all that well, doesn't prevent wear, and is an inferior lubricant, which is reason enough not to use it.
I highly suggest you guys read DIY Guys testing on top products. I can tell you this. Mobile 1 has a MUCH higher drag on your actions than the top 3 products in his list of 40+
"Drag on the action" from a good oil is negligible compared to the drag the oil *prevents*. The test you linked made the following assumption:
Excess lubricant acted like a glue that slowed or resisted parts from movement because of the surface tension and viscosity of the excess lube. As I removed more and more of the excess, I observed that less force was required to overcome static friction. In almost every case I found that removing all visible lubricant resulted in the lowest levels of friction between the two polished steel plates. What we have been told is correct, apply liberally to coat and then remove all excess to the point where you think you have removed too much and you will enjoy the least amount of friction. The side benefit to that dry level of lubrication is that it will not attract foreign contaminants that could get trapped in excess/wet lubricant.
For two flat plates, that makes sense. For a bolt-action, that might make sense. For a semiauto, that is a good way to hasten galling and promote carbon buildup, IMO, particularly something like an AR or AK where you have a lot of gas and carbon in the receiver. Over time on a "dry" surface, the powder residue accretes and cements into place, and can eventually hinder cycling, whereas a good oil will keep the carbon suspended for thousands of rounds as long as the lubrication isn't allowed to dry out.
In empirical testing, it has been shown many times that AR's and AK's work more reliably under adverse conditions when they are run wet than when they are run dry, and a good oil will not only protect the bearing surfaces better, it will form a thicker and more persistent film that stays "wet" longer.
I am amazed that people will pay as much as they do for firearms and then cheapo out on their cleaners and lubes.
So using a top grade synthetic oil in an AR rather than some petroleum distillate with magic teflon elves in it, or a decent lubricant diluted by a petroleum based solvent, is "cheaping out"?
I run what I find works best and most reliably for me, which is what pretty much everyone does, methinks.