Will Synthetic Molybdenum Impregnated Grease Harm My Rifle?

[Hoppalong Doc]

I guess the title of my post explains the question fairly well, but here's a quick background: I recently used the last of the suppplied moly grease for my Vortek Tune packages. I checked Amazon and ordered a can of moly grease by Valvolene. There was no indication that it was synthetic, except in the small print, which was unreadable on-line. Anyway, is this okey for my various airgun and rifles? Orv.

 

[Chief55]

I have seen videos of it used on the springs of spring guns to smooth them out and also the actions of PCPs. If I remember correctly from my aircraft mech days the main thing with MolyB is not to use it with real high temps like exhaust systems because it has carbon in it which would cause corrosion, not a problem with airguns. There seems to be some disagreement on using silicone oil on the piston seal.

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[Pumacarl]

Back in the early 80's, Beeman used to sell Pena-Dry. It came in a 4" high bottle that you would screw on a 3" to 4" long needle to put into the chamber of your springer. You'd only put a couple of drops in and it would lube up your chamber walls and piston seal. Pena-Dry was nothing more than Molybdenum Disulfide in an evaporating carrier. It was extremely messy if you weren't careful and seemed to work well. Moly for airguns has been around for quite a while. Most people these days use chamber oil which looks like silicone oil to me. I don't know if it has to be a specific weight silicone oil to be used as chamber oil, maybe it's just a packaging thing, I never remember reading anything on that. I'd be curious to know if it is just a marketing label, which seems most likely thinking on it.

With my FWB124's Pena-Dry was no problem because I could de-cock the gun to work the piston. With my HW I'd have to leave it cocked until the carrier fluid evaporated or it could diesel. I didn't like that aspect of it so I stopped using it. I did not modify my HW for de-cocking until 10 or so years later.

Moly anything, is not in itself, going to hurt your airgun. Beeman used to warn against using it in your trigger group because it was so slippery that it could make some triggers unsafe, that's the only caveat that I ever heard. Moly grease is what I use on my breakbarrels action, it's perfect for that.