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Discussion Starter #1
With the onset of "Social Distancing", I've had more inside time and I've been doing a lot more reading. I've been going through a big stack of Precision Shooting magazines from 96, 97, and 98 so far.

Nearly every issue had an article about the benefits of moly coated bullets. Some issues had several articles. All of them singing the praises of moly coating, or detailing how to produce the best coated bullets. (Rather like the recent adoption of powder coated cast bullets, but even more articles.)

Molybdenum Disulfide is a very black finely powdered compound that has very interesting lubricating qualities. It is biologically inert and nontoxic. It has one of the highest resistances to extreme pressure while still maintaining it's lubricity. The lubricating qualities are phenomenal in protecting against sliding (shear) forces but much less so against rolling forces. That means moly is much more useful in preventing two surfaces from galling or wearing, than it is for protecting bearings, especially roller bearings. Moly particles tend to become imbedded in the surfaces of the bearings with the result that they become less smooth and wear faster.

But back in the mid 90's, moly was thought to be a remarkable discovery as a bullet lubricant. Also, it was said to prolong barrel life, delay barrel erosion, eliminate the need for barrel cleaning, and increase barrel accuracy. It was supposed to do everything short of eliminating wind drift--although come testing suggest that moly would act to effectively increase a bullet's ballistic coefficient and thus maintain a higher down range velocity. The vast majority of long range and precision shooters--bench rest, high power, Palma, etc) adopted moly coating for their bullets. Most of the best known and most respected shooters lauded the benefits of moly and set records using it. Bullet manufacturers offered their products pre coated, and even a few ammunition makers produced cartridges with moly coated bullets.

Then, twenty years later, almost no one is using it. Why? What changed? Why has moly fallen out of favor?

That's not to say that using moly coated bullets had no disadvantages. But they seemed minor compared to the benefits. Moly was black and stained fingers. Unless care was used during the coating process, the moly powder seemed to get everywhere. The moly coating process for bullets was a bit cumbersome. Moly coated barrels were uniformly black inside and after being shot with moly bullets, cleaning patches came out with black streaks forever afterward. And if moly contaminated metal surfaces that should not be lubricated, it was very difficult to remove.

I got to thinking about this after working on my 7x57mm Mauser. I've had this since the early 90's and I used a lot of moly bullets in it at the time. One load using Rel 19 and moly coated 165 gr Nosler partitions was safe and accurate in my rifle at up to 3000 fps.

Moly coated bullets have less friction through a rifle barrel than do uncoated bullets, and typically have lower velocities with the same load of powder. They need about 4-6% additional powder to recover that velocity difference. Even so, it is though that the pressures generated in the chamber and barrel are lower with moly coated bullets (even with the additional powder) than with uncoated bullets.

It occurred to me that my loads with the moly coated 165 gr Noslers may not be safe with uncoated bullets. It seems I will have to continue using coated bullets, or start from scratch and work up new loads.

Anyway, why did the moly coated bullets fall out of favor?
 

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I was told several years ago that moly coated bullets make the barrel very difficult to clean. I cannot comment on personal experience, just hearsay. There is a lot of better informed people here than me.

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I understand that commercial needs ($) always require new solutions,
and that B.R. shooters first are constantly oriented towards each new experiment,
however, to date, I have never had to regret molycoating my bullets,
this also in my Mausers_
I talk about new and old carbon-steel barrels,
where I care about not only about performance,
but about a longer lasting life too, if possible. (I hope)_
In my experience, moly-conditioned barrels are quicker to clean from the gunshot residues after use.
it is understood that the moly must not be removed from the treated barrels,
unless I want to return to the use of uncoated bullets:
this can today be easily obtained with dedicated products or foams.
 

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I remember that the problems of sulphurous corrosion hypothetically due to moly were often concomitant with moly-barrels left in unfriendly environments and with little care. (obviously I am referring to what I read from U.S. sources, assuming I had translated and understood correctly).
To date, cleaning the shot residues from my m.barrels after use with a not particularly aggressive oil, and storing the same lightly lubricated inside, I have had no problems.
(I cross the fingers
)
 

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I have a couple of boxes of Federal Premium in .30-06 loaded with 180 gr Barnes XLC (Coated X Bullet). I never shot them after I started reloading and just got reminded I had them after reading this thread. I think I might post them for a trade locally, see if anyone is interested.
 

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Moly-lube the miracle engine treatment, even though this thread is all about boollets and shooting! it's still available for engines.

ca'jun56
 

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That's an interesting question. I was pretty active in High Power competition during the Moly craze and I knew several marksmen using coated bullets. As I shot for my unit's rifle team, I was issued good Lake City match ammo and so I never tried the coated bullets. I did listen to those who did while pulling targets or after a match either sing Moly's praises or complain about its foibles. While I was tempted to try it, but I never did get around to it and I now wonder, like the OP: What did happed to Moly coated bullets?

You know, this thread also brings up the question: What ever happened to cryo freezing barrels? That was once also supposed to be the end all for match barrels. I knew a few shooters who would invest their last penny in just one more 10 or X at 600 yards and they used barrels that had the cryo freezing process as well as Moly coated bullets.
 

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I think we tend to be a nation of "fads". I remember using a Moly additive in the motor oil of our delivery trucks in the 80's. We seemed to think we got some good out of using it but, it slowly faded out of use. They closed the Climax mine in Colorado and started importing from China. Seems like I heard the mine re-opened a few years ago.
That stuff is slick though.
 

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I used a batch of moly-coated in my 9mm. I know you guys are talking about rifle barrels, but barrels are barrels. Moly coating left a black coating in the barrel and if you are expecting to a bright shiney barrel after cleaning you'd think that your barrel was dirty, but it wasn't. I never bought any more because I didn't think it was worth the additional cost. I guess people didn't think it solved a problem.
 

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In the 70's the USAF experimented on some of our heavy ground radars to see if moly could be used to extend the life of antenna bearings since changing them involved tall specialized cranes in remote locations.
The result was that it's useless as an additive - it has to be bonded in a special process to show lubricating properties.
Steel was the only material mentioned for obvious reasons but since the process involved heat and pressure I doubt that bullets were using a bonded coating.
So all those moly engine additives are pure snake oil.
 

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I have a close personal friend, he worked in the Moly Room at Black Hills Ammo. The bullets were coated in tumblers, and the dust was everywhere, even with sealed tumbler doors. The microscopic Moly dust gets in your skin, hair, pores, clothing, and it creeps in to your wristwatch, glasses, and everything else. It enters the pores in the barrel steel, and becomes part of the metallurgy. It's very hard to wash off your body, and almost impossible to get out of a barrel, too.

It makes your barrel 'addicted' to the coated bullets, groups will actually open up slightly if you shoot standard slugs through a Moly saturated bore. After weighing all the evidence, BHA quit Moly coating their match bullets. The disadvantages outweighed the advantages. The advantages were questionable, too. A slight increase in velocity, and maybe, just maybe an increase in accuracy, but not in all rifles.
 

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In the 70's the USAF experimented on some of our heavy ground radars to see if moly could be used to extend the life of antenna bearings since changing them involved tall specialized cranes in remote locations.
The result was that it's useless as an additive - it has to be bonded in a special process to show lubricating properties.
Steel was the only material mentioned for obvious reasons but since the process involved heat and pressure I doubt that bullets were using a bonded coating.
So all those moly engine additives are likely pure snake oil.
Oh - I think they determined that the culprit was heat coupled with some other pressure effects from very large supported weights.
It *does* make a good lubricant for high load conditions much like graphite.
 

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Well I have one rifle that I used them in. I believe the old Winchester Failsafe bullet had Molly coat. My rifle loves them. I don't use that rifle much any more but when I do I have a couple of spare boxes. Don't fix what ain't broke. Nickel moa or less.

I dont one know what slick 50 had in it but it worked on my 78 K-10 Blazer. It had a 400 ci small block. Known for running hot.
Pone day after leaving the air base I stopped and picked up oil and a can of that. Changed the oil and filter with a hot engine. The took it out for a 50 mile jaunt and parked it. I the next day it was running much cooler and my gas milagle went up by almost 3 mpg. The down side I had to put cardboard in front of the radiator in the winter to have heat. Until I changed the thermostat. Never used it since though. In my case it was not snake oil.
 

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Slick 50 had Teflon it. Never used slick 50, but I am a big fan of Tri-Flow lubricants for use on my firearms. It seems, at least for me, to make barrel cleaning much easier. I first started using it back around 1980. I had a Colt AR-15 SP1 with a rough spot in the upper receiver, and after 20 or 30 rounds, the bolt carrier would tend to hang up occasionally. I tried several different lubricants, but Tri-Flow was the one that worked the best. I've been using it ever since.

As far as moly-coated bullets, I remember reading about them, but I never tried any.
 

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I first used them with the Winchester Fail Safe projectiles for an elk hunt. The projectile, Fail Safe, was similar to the Barnes X Bullet from what I remember but was covered in Moly. They worked great on elk that year but I didn't get the accuracy I had wanted when developing the load. After the season when I went to cleaning, the moly would not come out of the barrel. Yes it is just a coating but I get really picky on my bolt action rifles that I demand absolute accuracy out of them. To this day, my 338 Win Mag still has moly that won't come out of the barrel.

I think it was a trend for the time to sell people as stated earlier, everything changes every year to try and make everyone buy something new. I didn't care for it and wouldn't use it again in my rifles just because of the lasting effect of it staying in the barrel.
 

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It's the best thing I've ever seen for making a mess everywhere. Lord help you if you get as sudden gust through a window. I'm thinking that may have lead to it's disappearance.

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Discussion Starter #20
I'm not an apologist for moly coated bullets, but I'd like to understand more about them.

The bench rest shooters initially embraced them since they thought they could reduce their group sizes by 0.05-0.1". This is enough to move them from the top 25% to the top 5% of shooters at a match. These guys keep detailed records of every target shot--loads, conditions, bullets, temperature, wind, etc. They had the data to tell if moly was making a difference. (Evidently, that data eventually also convinced them to stop using it as well.)

The barrels were black inside. Copper fouling could not be easily seen. According to the wisdom of the time, on the other hand, there was almost no copper fouling when using moly. Cleaning could be done with one or two passes with a Kroil saturated patch, to remove the powder residue, and that was supposed to be all that was necessary. Moly was thought to preserve the accuracy potential of the benchrest barrels from about 1000 rounds to 2000 rounds or more. It was also thought to similarly preserve the barrels of the ultra magnums and fast wildcat calibers, which suffer bore erosion from the high pressure propellant gases by around 1000 rounds.

Although some moly coated bullets were commercially available, most users coated their own bullets in a rotary tumbler. I don't think this was commercially driven any more than is the popularity of stainless steel tumbling media.

It's interesting to me that that moly coated bullets were once considered to be essential to win shooting championships. All the big name shooters were using it. Then, no more than about 10 years later, it all but disappeared. I will continue to use moly coated bullets for some of my top loads. I think moly offers advantages in lowering internal pressures. My rifles and my shooting are not accurate enough to demonstrate improvement in group sizes.

Thanks for the thoughts and replies. Keep them coming.
 
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