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To molly, or not to molly, always in question...

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To molly, or not to molly, always in question... was created by crux

So persons who've purchased Armalite Rifles with match barrels will be familiar with the manufacturer's recommendation to break the barrel in with Match Ammo with a Molybdenum disulfide en.wikipedia.org/wiki/Molybdenum_disulfide coating on the bullets. They recommend Black Hills. They do not give any specific rationale other than it helps break the barrel in "faster".

Now I'm not sure I understand how it's supposed to speed the process up, but I will conceed that the lubricant properties of MoS2 ought to cause less wear on the barrel while "ironing it out" during the first hundred rounds.

I haven't seen any real good science done on whether it really makes a hill of beans either way. For that matter, there are those who swear on always shooting moly bullets, but there are those who will swear just about anything.

Personally I went ahead and followed the manufacturer's instructuions for break in (maybe it helped, maybe it just helped some backscratching between Armalite and Black Hills, who knows), and have shot straight copper jacket since then. I haven't noticed a difference between the last 20 moly, and the current fmj I'm using, and I'd have expected any moly remaining in the barrel to have thinned out to non-noticable status by this time. Perhaps long term lubrication with moly could theoreticaly have some effect on barrel life, but I'm not convinced it's worth the fuss for what difference there might be.

So, for those with experience or science with moly vs. not, what are your observations?
14 years 7 months ago #1938

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Replied by zfk55 on topic Re:To molly, or not to molly, always in question...

Moly leads to eventual buildup and the very good possibilty of bore corrosion when moisture on any level is introduced. Moisture and Moly = corrosion in your bore.

Read this first and then check the post below. www.patentstorm.us/patents/7197986/description.html

zfk55
Latigo

"When futile negotiating is done, when the corrupt politicians will not hear, when the voice of the citizens is ignored you will then face me under a different and final circumstance."

Col. Michael Hoare
14 years 7 months ago #1940

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Replied by weshowe on topic Re:To molly, or not to molly, always in question...

Gents,

The benefits of moly, in most cases, have been vastly overstated. Once popular with the bench rest crowd and then Hi-Power Rifle shooters, the process has fallen from favor, for the most part.

As mentioned above, there is the "build up/corrosion" issue. I see that as a non player in stainless barrels. Still, it might happen.

Some Hi-Power shooters still use it because of ease of cleaning. Plus, Hi-Power shooters get "sighters" to help warm up and condition the bore prior to shooting for record.

Moly makes your barrel last longer...not necessarily. What kills barrels is THROAT ERROSION. Moly doesn't help a bit, in that reguard, because it's caused by heat generated upon firing in the throat of the rifle.

If you use moly it's a bear to get out of the bore. Switching back and forth is contra-indicated...there ususally is a shift of impact associated with the change...sometimes a considerable shift.

Moly should be treated/sealed with a high grade wax and can attract dirt and abrasive particles...a no-no in barrels costing $600-$800 to buy and install on your rifles.

Sniper Country has several good articles on moly. One by Boots Obermeyer one of Americas oldest and most respected barrel makers...he advises against moly...that's good enough for me.

Some claim higher velocity. My testing show this to be negligible or non-exhistent. Usually, shot to shot variation is greater than percieved increase in velocity or purported gain from use of moly.

You won't find any moly used in my high grade rifles, tactical rifles, or varminting rigs.

Enough said. DON'T DO IT...

Wes
14 years 7 months ago #1943

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Replied by crux on topic Re:To molly, or not to molly, always in question...

Good stuff.
I'd still like to see some science done just to lay the issue to bed. That said, I don't see any clear demonstrable reason to fuss over shooting anything but FMJ.
14 years 7 months ago #1945

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Replied by Scaup58 on topic Re:To molly, or not to molly, always in question...

www.varmintal.com There's some good info here on moly and
    lots
of other reloading stuff.
14 years 7 months ago #1946

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Replied by weshowe on topic Re:To molly, or not to molly, always in question...

Gents,

I'll have to visit the Armalite site and see what they say about moly and their barrel break in process.

My own G.A. Precision rifle has never had a factory tube on it and sports a Schnieder 11.25" twist .308 barrel.

Several very good barrel makers have said that barrel break in is unessessary. Siteing the fact that they use a 32 micron finish on their tubes they wonder just what you are lapping?

Fire lapping, etc. probably helps the less expensive barrels, but not the really good match grade stuff. After all how are you going to get a finer finish than 32 micron?

Still, I do break my barrels in...it doesn't cost anything AND it just might be helpful.

Wes
14 years 7 months ago #1948

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Replied by zfk55 on topic Re:To molly, or not to molly, always in question...

If you've been following the thread on the Stewart Wilson AR10, this is an email about our rifle and barrel break in. Bear in mind that this is a long term builder who makes contract rifles for the military and is now the head field instructor for E.D.M.
Since beginning our series of tests he's now considering hBN in lieu of Moly, but also note that his Moly process involves definite post-session cleaning and maintenance of the barrel...... every time without fail.
Because of his promotion of the Sierra within the contract rifles, he has a deal with Sierra to supply him with any amount of 175 SMK Molys upon request.
From: xxxxxxx
To: xxxxxxxx
Sent: Sunday, August 09, 2009 6:15 PM
Subject: Yo!

Pierre, HBN is definitely viable. Go for it.

You can do your own moly process. You have to find laboratory grade mds (moly). or, by all means, do the hbn process.

The article you highlighted is the preferred method for any of the processes. Good material.

The process on the barrel, probably requires some explanation. All of the properties applied, from the parent barrel material to the finishing process (electro-polishing) inclusive of the taper bore (there is a slight taper from breach to muzzle - about .0006" , that's six ten thousandths of an inch.) This achieves a couple of desired conditions: 1) linearization of the surface molecules of the bore surface {as you no doubt are aware from your machine tool background, every time a cutting tool touches the material a 'crust' is formed. This crust is what "barrel break in" is meant to correct. This is also, why 'break in' is minimal on your barrel}. Secondly, the taper configuration of the barrel, in affect, creates a freebore situation for the entire barrel length. Or, another way of looking at it is the barrel achieves a more uniform, or normalization condition for the bullet being pushed down the bore. All this achieves more even or consistent muzzle velocities which tightens standard deviation.

The point of all this is - barrel life!!. Instead of replacing that barrel every 3000 rounds or so, how about, well, I really don't know as yet. I have one of the first units built (my AR10s), a 24" version of yours that has 9700+ rds out of it and it is still a 1/2 MOA rifle!. There are those that have declared that we will have a wake for it when it's "shot out". The goal sought after was longevity. There was no data when I put the formula together some years back. It took time to demonstrate the objective.

Moly coating (or any process that augments the barrel surface 'normalization') is just part of the matrix.

I would hate to think that you would be waiting (in limbo) to shoot the rifle because of a shortfall of resources here. I am sure there is an answer somewhere with HBN. Let me know of the solutions you come up with. I used to have some moly, I am sure that I still do, - I just am unable to find it in all the crates scattered about in my life right now.

Keep me posted here.

Stewart
Original Message
From: xxxxxxx
To: xxxxxxxxxx
Sent: Saturday, August 08, 2009 5:33 AM
Subject: Re: Yo!


Good morning, Stewart.
I don't want to take a lot of your time with this, but I've determined that buying/waiting for Moly coated projectiles is going to be a three to five month wait, this accodring to Sierra.
Would you mind taking a brief look at the following link. I'm a 45 year reloader and avid projectile caster, so I doubt I
d have much difficulty with this process.
My question concerns the use of HBN in lieu of Moly, but if the Wilson AR10 requires Moly as the lubricant, then of course we'll use Moly. The link is here..

www.patentstorm.us/patents/7197986/description.html

Thanks for your help, and we're huge fans of this rifle. Despite parting with substantial cash to obtain it, we're honored to have it.
Pierre
Latigo

"When futile negotiating is done, when the corrupt politicians will not hear, when the voice of the citizens is ignored you will then face me under a different and final circumstance."

Col. Michael Hoare
14 years 7 months ago #1949

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Replied by weshowe on topic Re:To molly, or not to molly, always in question...

Gents,

Interesting letter from this Stewart fella. I don't know what his bona fides are, but anyone that talks about replacing a .308 barrel after 3,000 rounds is way off base. Unless he's talking belt-fed weapons, in which case accuracy is not an issue and they go way beyond that miniscule number of rounds down range.
I'm neither FOR OR AGAINST moly. If you think it's beneficial then use it. What I've found is that it gives no worthwhile benefit to me. Mind use that's observable or measurable benefit.
Non-moly barrel life? I have more than a little familiarity with the Marine Sniper M40A1's and A3's chambered in .308. It's not uncommon for them to exceed well over 10,000 rounds and still retain "sniper" grade accuracy. A number of these rifles have gone as high as 15,000 rounds of M-118LR withough re-barreling.
For those not familiar with the M-118LR it's the current issue sniper round for the Army and Marines using the 175 gr. Sierra Match King bullet. It is, of course, not moly coated.
Stewart talks about getting 9,700 rounds out of his AR-10 like it's due to moly or his building prowess. Neither may be the case, because that would be NORMAL barrel life in any .308 match grade barrel.
I'm about tired out on the subject. Use it or not...your choice. This old Marine will contine steer clear of moly, as does the Marine Corps, as does Weapons Training Battalion, Quantico. The builders of the most accurate sniper rifle in the world.

Wes
14 years 7 months ago #1954

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Replied by zfk55 on topic Re:To molly, or not to molly, always in question...

He's well known at Quantico, Wes, and he began all of this in the mid 80s. I'd wager I've been around as long as you have with my service having been in the 50s.
Better for a man to read everything pertainig to the man and understand the premise before discounting something firearms related in an area about which he has little in-depth current knowledge, as did I until recently. You want to know who Wilson is? Read this and then read the thread about his latest Walther Naval Contract rifle. The one with which we're now experimenting. There are reaspns for everything surrounding these particular rifles. It appears that the Marine Corps agrees with him now and has for quite a while.
Very respectfully, you're a bit too quick on the draw, Wes.

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Latigo

"When futile negotiating is done, when the corrupt politicians will not hear, when the voice of the citizens is ignored you will then face me under a different and final circumstance."

Col. Michael Hoare
Last edit: 14 years 7 months ago by zfk55.
14 years 7 months ago #1955

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Replied by weshowe on topic Re:To molly, or not to molly, always in question...

zfk55,

Intersting article. I have no doubt that Quantico knows Mr. Stuart. They know a lot of people who are trying to sell them on new ideas.
Mind you, I'm not taking a shot at Mr. Stuart, his products or ideas, etc., but I'll just about guarantee that the Marines are not issueing semi auto AR-s. Testing some, maybe. Really, that's not a bad idea tho' after the years of the Army trying to get a gas guns to shoot including the SR-25. Marines finally gave up on the M14/M21/M25.

Boots Obermeyer basically saved the SR-25 program by providing barrels that worked instead of the issue Knights Armament tube. Last I heard, several years ago, Boots had provided the Spec Ops folks with over 1,000 20" 5R tubes that gave them the velocity they needed without using a 24" barrel. He LITERALLY saved that program. I've known Boots for years and when the man talks barrels I listen. He's forgotten more about barrel making than most ever knew. Unless he's had a serious change in position he eschews moly.

Let's face it. Whether it's Mr. Stuart, Boots, or others we are lucky they continue to push the envelope. Us users are the folk who benefit.

I'm all for the Marines getting a good gas gun, but when they do you can damn well bet it will be built by the lads at Quantico and not purchased off the shelf. Marines, being traditionalists, will still use bolt guns for the benefit they provide. In the current fracas the firepower of a good semi-auto combined with stellar accuracy would keep the lads from humping two rifles, as some are doing.

Let's stay in touch. I have A LOT to learn about AR-10's so would like to pick your brain a bit. I may even have info that might help you, too.
My phone is: 503-391-6847 and e-mail: whowe05@msn.com. The same for others...hit me off line if you'd like.

I'm primarily a bolt gun guy and always will be. I also see the benefits of the gas gun.

Back to moly...if moly is so damn good how come M118LR isn't moly coated?

STILL standing firmly against moly except for special use where it's benefits can be measured, documented, and seen.

Wes
P.S. Perhaps I should change my nom de plume to "Quick Draw"...;-)
P.P.S. I entered service in 1970 and retired from the Corps in 1994...
14 years 7 months ago #1959

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