Moly Lube question

Discussions of powders, bullets and loading information.

Moderators: Kirk, Lucinda

Post Reply
4570faraim
Posts: 4
Joined: Mon Feb 12, 2018 10:29 am

Moly Lube question

Post by 4570faraim »

I'm just getting started and have been shooting bullets with SPG lube. I picked up a batch with a dark grey lube, which I suspect has some moly in it. From my smokeless shooting days I remember that once you shoot moly coated bullets the bore becomes imbedded with the stuff. From then on whenever you clean some dark residue will come out on your patches. Is it the same with the black powder lube, or can you eventually get clean patches after shooting moly? I'm concerned I may not be able to tell when the black powder fouling leaves off and the moly residue begins. Thanks.
SchuetzenDave
Posts: 864
Joined: Mon Jan 07, 2013 9:07 am
Location: St. Albert, Alberta

Re: Moly Lube question

Post by SchuetzenDave »

NEVER NEVER use MOLY in a BPCR.

Moly with metal friction and moisture (from Moose Milk or Water soluble solutions) can create a carbide like substance that adheres to the inside of your barrel.
It CANNOT be removed.

I have seen one of my friend`s barrel destroyed this way.

Moly works fine with smokeless powder rifles cleaned with solvents that are not water soluble.
NMLRA Past Pres.
Posts: 180
Joined: Fri Mar 24, 2006 7:48 am

Re: Moly Lube question

Post by NMLRA Past Pres. »

Hello:
Thanks, Dave, for the warning. Never heard that before.

Have not considered moly as a BPCR bullet lube, but use it mixed with lithium based wheel bearing grease as a steel to steel lube.

Am amused to see people recommending graphite, which I understand to be an abrasive.
Have seen several molds with significant galling between top of blocks and bottom of sprue plate near screw from " mold prep" that is an alcohol-graphite solution.

Anyway, I am fascinated by and most appreciative of your advise.

Can you please share more about the moly problem and how it forms the deposits?
Thanks,
Kevin Tinny
Pay attention to that soft voice in your head.
Trust a good woman. Her brain IS hardwired differently than a man's.
Most women can smell sin over the telephone; try it sometime. Haha. Love.
SchuetzenDave
Posts: 864
Joined: Mon Jan 07, 2013 9:07 am
Location: St. Albert, Alberta

Re: Moly Lube question

Post by SchuetzenDave »

Room Temperature Friction of Molybdenum Disulfide
Article in Tribology Letters 53(1):1-8 · January 2013 wDOI: 10.1007/s11249-013-0273-0

Harman Khare

14.42University of Pennsylvania

D.L. Burris

31.94University of Delaware



Abstract
Molybdenum disulfide (MoS2), a lamellar solid lubricant, is used extensively in space applications due to its exceptional performance in vacuum and inert environments. The friction and wear of MoS2, however, increase in the presence of atmospheric contaminants, such as water. Despite numerous studies of the moisture-sensitive friction response of MoS2 over the decades, important fundamental questions remain unanswered. Two leading hypotheses suggest that water affects friction by causing the MoS2 to oxidize or by physically bonding to edge sites, and thereby disrupting easy lamellar shear. This paper presents a parametric study to (1) isolate the effects of water and oxygen on ambient MoS2 friction, (2) identify the effect of water and oxygen on MoS2 oxidation, and (3) distinguish between the effects of water diffusion and surface oxidation on the frictional response of MoS2 coatings. The experimental findings were used to develop a qualitative model for the effects of environment on MoS2 friction; the model is used to explain transients, hysteretic effects, oxidation effects, and effects of physically bound water.
NMLRA Past Pres.
Posts: 180
Joined: Fri Mar 24, 2006 7:48 am

Re: Moly Lube question

Post by NMLRA Past Pres. »

Thanks, Dave:

That paper will amaze some of my gauge-maker friends that have sworn by Moly on steel-to-steel contacts, especially high pressure ones.

Guess I'll switch to plain wheel bearing grease.

Life's a learning experience. Your sharing, to keep us from costly mistakes, is what this Forum promotes. Smiles and bows to you.

All the best,
Kevin Tinny
Pay attention to that soft voice in your head.
Trust a good woman. Her brain IS hardwired differently than a man's.
Most women can smell sin over the telephone; try it sometime. Haha. Love.
User avatar
Lumpy Grits
Posts: 7675
Joined: Tue Jan 28, 2003 7:58 pm
Location: Springfield, Missouri-U.S.A. Earth

Re: Moly Lube question

Post by Lumpy Grits »

I have used Sta-Lube Engine Assembly Lube for decades on firearms.
https://www.amazon.com/Sta-Lube-SL3333- ... B000CPAWP6
Never and issue-
NO-I have never used it for a bullet lube.
I have shot lots of moly coated, jacketed bullets in my long range modern bolt guns and removing the moly ain't hard.
G.
"Hav'n you along, is like loose'n two good men"
hepburnman
Posts: 111
Joined: Tue Nov 09, 2010 10:39 am

Re: Moly Lube question

Post by hepburnman »

What exactly occurs in a BPCR barrel after the use of a moly-based lube? How has a person's barrel been destroyed? There was such a lube that was offered by Lee Shaver some years ago which I used back then. Cant say that I have seen any ill affects through its use. Rifle shoots as accurate as ever.
SchuetzenDave
Posts: 864
Joined: Mon Jan 07, 2013 9:07 am
Location: St. Albert, Alberta

Re: Moly Lube question

Post by SchuetzenDave »

Friction of metal on metal in combination with moisture in the barrel CAN result in oxidation of the Molybdenum disulfide (MoS2) which reduces its ability to act as a lube plus it MAY be physically bonding to edge sites (i.e. land edges).

Oxidation of Molybdenum disulfide can create a CARBIDE LIKE material that is so hard and so physically bonded to the barrel that it CANNOT be removed.

Does it always happen? NO

What is required for it to happen in a barrel? Moisture must be present: which is more frequent after cleaning BPCR barrels i.e. repeatedly after each shot.

The person I saw that had it happen travelled to the range on a cold (just above freezing) humid day and there was condensation of moisture in his barrel without his knowledge.
He was a very professional machinist and everything he tried could not remove the oxidized Moly that had adhered to the barrel.

Why does it adhere to metal edges on occasion? The scientists are trying to figure that one out.

Note: Some people will not be able to see the adhered carbide like film in their barrel - and may only notice increased leading of their barrel or increased group sizes caused by this fouling which is far more aggressive than the usual leading in a barrel.

In the damaged barrel I viewed; it looked like a couple of small tiny spot welds sticking up on the edges of his lands in a few places.

Metal friction is another requirement. The damaged barrel was a micro-groove barrel, so it may have provided more friction than normal deeper grooved barrels.
SchuetzenDave
Posts: 864
Joined: Mon Jan 07, 2013 9:07 am
Location: St. Albert, Alberta

Re: Moly Lube question

Post by SchuetzenDave »

For more information on the chemical formation of Molybdenum Carbide or Hybrid Structures Search for:


Epitaxial Synthesis of Molybdenum Carbide and Formation of a Mo2C/MoS2 Hybrid Structures via Conversion of Molybdenum Disulfide
User avatar
Lumpy Grits
Posts: 7675
Joined: Tue Jan 28, 2003 7:58 pm
Location: Springfield, Missouri-U.S.A. Earth

Re: Moly Lube question

Post by Lumpy Grits »

First I have ever heard of this issue. :shock:
My LR bolt guns all have SS barrels and I seldom clean them in between outings to the range.
I do live in the Mojave desert..... :lol:
G.
"Hav'n you along, is like loose'n two good men"
SchuetzenDave
Posts: 864
Joined: Mon Jan 07, 2013 9:07 am
Location: St. Albert, Alberta

Re: Moly Lube question

Post by SchuetzenDave »

I do live in the Mojave desert.....

And you are not blowing (blow tubing) either? :roll:
User avatar
Lumpy Grits
Posts: 7675
Joined: Tue Jan 28, 2003 7:58 pm
Location: Springfield, Missouri-U.S.A. Earth

Re: Moly Lube question

Post by Lumpy Grits »

SchuetzenDave wrote:
And you are not blowing (blow tubing) either? :roll:
:twisted: YES, on the BT use. :roll: :lol:
G.
"Hav'n you along, is like loose'n two good men"
Post Reply