Why wouldn't Mobil 1 work for your rifle as a really good bore lubricant? It withstands high temperature is not mineral oil based therefore contains no sulphur. Even at 4.50 a quart its still way cheaper then conventional mineral based oil by a wide margin .What would be wrong with using it?

Good point OEH, thats all I have ever used in my 2000 Ram and it has
over 150,000. I bought it New off the show room floor cause it is
5 on the floor. It has commpression like a new one. I also agree it will
work in a copper to metal rifle barrel at high pressures. I have often thought of
this myself, but have never tried it.

RH that is all I have used for both my cars in the last 5 years and never had an oil related problem as well. Seems like a low viscosity blend would be ideal.

Several reputable gunsmiths that I know have spoken of using it with good results. As soon as the drum of Break Free I have is empty, I'm gonna try it. Roskoe

Well, I used Amsoil for years and have recently gone to Mobil 1. I can tell ya that I have done my homework on this issue and the main (if not the only) benefit to synthetic motor oil is in its reduction in friction. Conventional motor oil has molecules of varying sizes (from small to extremely large). With synthetic on the other hand all molecules are of uniform size and they are about half the size of the smallest of petroleum based molecules. Something like comparing a larger tertiary protein to an amino acid.

So for metal to metal contact the synthetic will penetrate better and drastically reduce friction and in my opinion it would be great for firearms in such applications. Where synthetic lacks adequacy is in its ability to displace moisture and prevent rust. In an automobile engine the oil pump is continually drenching it with oil, so this issue is not a concern. Rust prevention would be a weak point for synthetic in a firearm application, however.

In air rifles and paintball guns, petroleum based oils are a big no-no. Since both use a number of rubber o-rings, a petroleum based oil would quickly break the rubber down. My RWS air rifle gets nothing but RWS airgun oil. This can apply to modern firearms as well. Bear in mind that if there is any rubber seals, o-rings, etc on your gun anywhere, it should not be oiled with a petroleum based oil.

Zac76156 what oil would you recommend ?..I have been using remoil for the bores

Dad gone OEH, you going senile? I would say mobile one is very, very heavy lube for guns. Not near as light as rem oil. Better clean it out real good before that cold bore shot.

BC it is actually very thin oil and after posting this I did a search on using that oil for that purpose and there were some hits. I just don't want something in the bore that doesn't displace moisture and allows corrosion. I don't know about you but after using an ammonia based solvent to remove copper I think Remoil is kinda flimsy to keep that bore protected.

I am going stupid myself. I took the advise of a gunsmith who told me to clean out that ammonia with brake cleaner and then coating it with a good oil.

It is a concern. But after cleaning numerous times on a gun, I recently looked at the bore and there was no pits or anything. So I must be doing something right.

I am just not sure that motor oil alone displaces moisture but might trap it? does that make sense or am I way off base. I am not a chemical or pretro engineer so am open for an education for one that might know.

OEH, when I was servicing time movements on bank vault doors,
I used Moebius grease on the pivot points. It was swiss made for
clocks and movements of all kinds. It is the grease from the Jaw
Bone of the porpose. I think it was world banned. Still have a small
jar and have used it in the action of my rifles. On the locking devices
of the vault doors, I used Super Tect white grease. Highly resistant to
water or evaporation and will not harden or break down under pressure.
Lubriplate White Grease is also good, it is used on the lower case of
Out-Board engines. I use clock oilers to pin point lubeing on my guns.
I also have an ultrasonic cleaner for parts and an Electronic Bore Scope.
All these things I used on Safe and vaults before I retired.

The Rem Oil contains Petroleum Distillate. The Hoppe's9 is a better oil.
It is a pure lubricant that will not gum, run or turn rancid. It will not
harm your stock when stored up-right and will prevent rust also.