Moly bullet coating

[Matt304]

I have a new barrel coming soon for a .270 target rifle, and I'm thinking about going the route of moly coating with my loads for it.

How are most of you moly coating your bullets? Is it worth the added effort for you?

What are the main advantages, besides barrel life?

 

[wingman]

I can only tell you my experience with moly coating bullets for a 1911 45acp
while the accuracy and function were fine it damaged my barrel in that pitting
was visible after a few hundred rounds and I always cleaned after shooting.

I replaced barrel and never used moly again however i know people who have
used it without problems and rave about it but for me I see no value with it.

 

[Slamfire]

Moly coated bullets is one of those fads that is slowly fading away.

It came on with the strength of a hurricane when David Tubbs, the winnest Highpower competitor ever at Camp Perry, used moly coat bullets, and won. David Tubbs is an exceptional shooter, and experimenter, so it is possible that there was something to moly coat, but on the other hand, if you are not as good as Mr. Tubbs, it is unlikely that you will see difference on paper.

I have talked to a Long range champion, who is my bolt gun smith and he gave up moly coat after using it for several years. The most important reason was that his shooting average was one point less with moly coat, the second reason was that moly is a mess to deal with. You get it on your fingers, it gets on the bench, in the house, the kitchen, etc.

Fewer and fewer top shooters now use the stuff.

At the time moly coat was at its height, the proponents of it claimed all sorts of benefits, besides increased accuracy, barrel life was supposed to triple, velocities were supposed to increase, and you never had to clean your barrel, etc.

About the only one that is supportable is that greasing your barrel does reduce friction, so pressures are less at the same velocity.

I always thought moly was just another thing to go wrong, and since the claimed benefits have proven unsupportable, or just bogus, I don’t plan to ever use moly.

And I don't recommend that anyone does. I have been told that once you get that stuff in your barrel, it is hard to remove.

 

[Walkalong]

Slamfire1 really covered it well.

Benchresters tried it, and 99% have given up on it.

David Tubbs could win shooting a Mil-Surp. Well, just about anyway.

 

[gtmerkley]

Let us know how that turns out.

 

[30Cal]

I did it for about a year using a tumbler and a peanut butter jar. 100-200 bullets at a shot for 90 min.

I didn't really see any benefit that made the extra effort worthwhile.

If you shoot moly, make sure you have a film of oil in the barrel if you're not shooting. My rifles were in a humid environment at the time. The one I shot moly through developed a moderate case of pitting. The other rifles were fine.

 

[W.E.G.]

I've used it quite a bit.

Shot good scores.

Probably would have shot good scores anyway.

Moly'd several thousand bullets...

...and the family room, and the library, and the baby

wife was not happy.

I don't use moly anymore.

 

[cracked butt]

Moly is sooo 2001.

At the time moly coat was at its height, the proponents of it claimed all sorts of benefits, besides increased accuracy, barrel life was supposed to triple, velocities were supposed to increase, and you never had to clean your barrel, etc.

About the only one that is supportable is that greasing your barrel does reduce friction, so pressures are less at the same velocity.

You also have to stuff more powder in your cases to get the same velocity as non-moly treated bullets. But yep, your analysis is spot on.

 

[.38 Special]

I strongly dislike the stuff. Never saw that it helped with accuracy, but it does make a big mess and is damn near impossible to get out of the bore.

 

[MCMXI]

If you shoot moly, make sure you have a film of oil in the barrel if you're not shooting. My rifles were in a humid environment at the time. The one I shot moly through developed a moderate case of pitting. The other rifles were fine.

I bet that was a steel barrel right? I'd be surprised if molybdenum caused pitting on either active or passive 316 stainless (commonly used for stainless steel barrels).

I shoot Sierra MatchKing HPBT "moly" bullets with no complaints. I haven't had any corrosion or moly fouling problems. I shoot them to reduce copper fouling but once my Kreiger barrels arrive I may switch back to copper since Kreiger barrels don't suffer from copper fouling the way off-the-shelf barrels do.

 

[TexasSkyhawk]

What are the main advantages, besides barrel life?

Main advantage is you get to keep trying out new barrels after the moly has helped pit and rust your previous barrel out.

Jeff

 

[ilike2hunt]

While I don't coat my own, the only bullets that have ever been shot through my 22-250 are Moly bullets (mostly vmax moly), factory or handloaded. My barrel is perfectly fine, no pitting, and shoots great.

 

[04JRB]

I bumped into a guy at the range last weekend who had a custon target rifle. I asked him about the rifle and what he likes for his handloads as we were both shooting .308win. The rifle was pretty sweet, 700 action w/ ss heavy barrel, blah blah...

He was shooting moly coated bullets, I asked if he was having success with it because I have never used moly and I was jsut being friendly during the target check. He told me, "I am shooting the last bit of the moly bullets and phasing them out of inventory because something was causing the moly to react with something in the firing process and etching the barrel."

Ive never heard this before. and after reading some of the members responses here, maybee he wasnt pulling my leg.

Either way, I dont see any reason for trying moly out and dealing with the mess. I will gain more accuracy from trigger time and improving my abilities, some day I may even be able to shoot as well as my rifles are capable of, lol.

 

[Matt304]

That's enough persuasion for me, guys. I'll steer clear of the whole idea.

 

[MCMXI]

Main advantage is you get to keep trying out new barrels after the moly has helped pit and rust your previous barrel out.

Any barrel that isn't cleaned and oiled properly can corrode regardless of whether you shoot moly coated bullets or not.

but it does make a big mess and is damn near impossible to get out of the bore

Sierra moly coated bullets don't make any mess at all and I've never had a problem with moly (from Sierra bullets) fouling the bore. However, copper fouling is a big problem in many off-the-shelf barrels so what's the solution? In my experience (anecdotal and NOT scientific I know), moly coated bullets (from Sierra) DO reduce copper fouling. I am always open to learning new techniques or procedures so if anyone has advice on ways to avoid copper fouling I'm interested.

 

[CBS220]

It's a mess to use, and unless you also treat your barrel you won't see much benefit. Not that the moly and moly coat is all that expensive, it's just a PITA to do it.

Also, molybdenum disulfide is hygroscopic, in that it "draws in" water, and makes barrels rust if not well oiled.

Too much trouble for too little gain! There are good coatings out there on factory bullets if you are of a mind to try them.

 

[dagger dog]

Wasn't the main advantage less copper fouling in high volume shooting? The p-dog shooters used to swear by it (not at it). But they are shooting 1000 rds. at a session.
I think the reply of it being a fad is correct though, you see less and less about moly in the ads.

 

[CBS220]

Any barrel that isn't cleaned and oiled properly can corrode regardless of whether you shoot moly coated bullets or not.

Unless you have put corrosives in it or leave it in a humid area, your barrels will be just fine for the most part... although cleaning is always a good idea to promote accuracy and function.

However, copper fouling is a big problem in many off-the-shelf barrels

Copper fouling is a problem in all barrels. When you push a copper-clad pill down a rifled tube at 2500+ fps, you're going to get some copper fouling, regardless. The uniformity (Or whatever other voodoo they put into mid-high range barrels) of a Krieger tube may lessen the fouling very slightly, but not so much as many are led to believe.

But if it shoots well for you, then stick with it. There is a reason why they still offer moly coat bullets in so many forms from the factory, and that is because people shoot them. It may be just as mental as a golf game

 

[MCMXI]

The uniformity (Or whatever other voodoo they put into mid-high range barrels) of a Krieger tube may lessen the fouling very slightly, but not so much as many are led to believe.

CBS220, I really hope you're wrong about that since I ordered two Kreiger barrels. They lap the barrels to a 16 micron finish which is supposed to reduce copper fouling a lot. I really don't enjoy cleaning my rifles with copper-removing cleaners ... it's a pain in the a$$. Anyway, this moly debate is interesting and as I said, I learn every day and am always open to change as new information becomes available. I load Barnes TSX bullets for hunting and they have a different approach to reducing copper fouling. There are annular grooves around the base of the bullet for that purpose.

 

[CBS220]

Don't get me wrong- Krieger makes a great product. There's a reason they are so popular with the competition crowd.

But all rifles accumulate SOME copper fouling in the course of being fired with copper-jacketed bullets. That's simply the physics of it. If you're paying for high-end barrels so you have to clean less often, I think you're missing the big picture

Most factory barrels are not the copper mines that some would have you believe, though. You'll notice a difference in accuracy, but I doubt you'll see much of an improvement in the time you spend cleaning!

Like I said, though, if it works for you, great! It's just that I tried moly-coating and moly bullets for a while, and while I never suffered from rusty-barrel problems, I never got any great gains, and I always ended up with moly coated hands... and pants... and everything else at the end of a session.

The new Barnes bullets are really good, btw. I like them a lot, the few boxes I have shot. However, the originals were a nightmare if you hated cleaning out copper residue.

 

[Auburn1992]

How much shooting of moly coated bullets has to be done before pitting can be seen?

Makes me rethink using Hornady VMAX moly coateed in my 22-250.

 

[MCMXI]

How much shooting of moly coated bullets has to be done before pitting can be seen?

This is possibly a corrosion issue rather than a wear issue since the concern is the formation of galvanic couples between the moly and steel of the barrel. Generally, galvanic couples require an electrolyte. A well-maintained (clean and oiled) barrel that is kept in a reasonably dry, low chloride environment shouldn't experience any pitting due to Moly coated bullets. So the short answer is that pitting of the barrel can occur within minutes under the right circumstances but conversely, it may never happen if you take care of your kit.

 

[MCMXI]

By the way, copper, lead and molybdenum are all noble compared to mild steel, 410 stainless steel, 304 stainless (active) and 316 stainless (active). So what does this mean? If you immerse a steel or stainless steel barrel with copper, lead or moly fouling into an electrolyte you're going to see the barrel corrode at a faster rate compared to a pristine steel barrel in the same solution. The point is, copper and lead fouling in a barrel can cause pitting too if not looked after properly.

I just found some information here on galvanic compatibility and the anodic index.

A copper-steel couple has an AI of 0.5V
A lead-steel couple has an AI of 0.15V

Here are the recommendations re the anodic index:

* For harsh environments, such as outdoors, high humidity, and salt environments fall into this category. Typically there should be not more than 0.15 V difference in the "Anodic Index".
* For normal environments, such as storage in warehouses or non-temperature and humidity controlled environments. Typically there should not be more than 0.25 V difference in the "Anodic Index".
* For controlled environments, such that are temperature and humidity controlled, 0.50 V can be tolerated. Caution should be maintained when deciding for this application as humidity and temperature do vary from regions.

Nothing about moly here but it just goes to show that particulary copper and possibly lead fouling can cause pitting in harsh environments. Copper fouling may even be a concern in "normal" environments!