# Moly coating



## BigDaddy (Mar 4, 2002)

Does anybody use moly coating? What have been some of your experiences?

I have been checking out the ballistics of the Barnes solid copper bullets. They look like great bullets, but I bet a person needs a case of copper solvent. I was thinking that moly coating might prevent copper fouling. But I have also heard that once you go moly, you can't go back.

Any advice?


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## born to hunt (Mar 13, 2002)

Big D

What did you ever find out about moly coat? I ended up getting a Rem 700 .22-250 with bbl and but a Leupold 6-18 VX II on it. I lapped the barrell and am ready to load. What about Moly? :sniper:


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## BigDaddy (Mar 4, 2002)

Born to Hunt<

What have I learned about moly coating? Well, I've talked with several people and here goes:

The moly coating is molybemum disulfide, and it is becoming more and more popular.

PROS
Moly coating acts as a lubricant in the barrel, reducing friction as the bullet travels down the barrel. The results are a truer flight, slightly greater muzzle velocity, and a greater ballistic coefficient. Moly coating also reduces fouling and can reduce the amount to cleaning required. For solid copper bullets, such as the Barnes bullets, moly would be a big advantage and save lots of time cleaning with copper solvent.

CONS
A by-product of molybdemum disulfide and water is sulfuric acid. Therefore, if a barrel gets wet, you need to clean very well. I visited with a gunsmith who had one customer ruin barrels of two rifles because he did not clean them soon enough. Also, going back to "non-moly" is probably impossible since getting the moly back out of the rifling is very difficult.

CONCLUSIONS
There are some benefits to using moly, you just have to be careful with moisture. However, there is most likely no going back... once you have gone moly, you probably can't go back.

Big Daddy


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## Ace25 (Dec 18, 2004)

good info on the molly, One other tidbit of information that I learned; You generally need to fire 4 or 5 rounds in order see the greatest balistic benifits of molly coated bullets. If you are at a shooting match and they allow more than 5 shot sighters, great, otherwise, I would probably stay away from molly... (she's mine) LOL J/K


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## Plainsman (Jul 30, 2003)

There are many misconceptions about molly. Go to a gun show and you see many self proclaimed experts that know very little of which they talk.

I have heard molly will build up and you can't get it out. No, but if you wax your bullets (carnauba is common) it can build up in your bore, and is nearly impossible to get out.

If you want molly out of the bore use JB Bore past. This will take you back to bare metal.

Molly with the same load will actually give you lower velocities because it lowers breach pressure. However, because breach pressure is lowered you can add more powder, and yes then you exceed the velocities possible with non molly bullets.

I don't know about molly changing to acid, I have left rifles uncleaned for months, with no negative effect. I will brush carbon from the bore, but I have many rifles that shoot better after ten to fifteen fowling rounds, and I don't want to shoot a box of shells every time I want accuracy.

The reason you get a better ballistic coefficient is that molly is so slippery that the bullet is not engraved as deeply by the rifling. This isn't good for Barnes X bullets. I have molly coated Barnes X bullets, and when I do accuracy goes out the window. Bullets obdurate slightly when fired. Copper is so hard that they do not do this well and hence have shallow rifling groves on the bullet after they pass out the barrel. I think they loose their accuracy with molly because the engraving is insufficient, or so shallow that the bullet doesn't stabilize.

I ;have a kit from Midway that I use to molly my bullets, and I use molly on most of my bullets.


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## Whelen35 (Mar 9, 2004)

I have also read about the water problems with molly. If this is true, then would cold weather hunting be more of a problem if you take your cold gun into the house and condensation takes place. I have no first hand working knoledge of this, so it is more of a question as well. Also, would this moisture tend to be trapped between the steel and the molly coating? No answers here, but more questions.


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## Plainsman (Jul 30, 2003)

I can't find any information on moly and acid. I think I will take an old rifle barrel, polish the outside to bare metal, moly cote it, leave it out in the cold, and bring it in the house so water condenses on it. I think I will do this a half dozen times and see what happens.


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## Ace25 (Dec 18, 2004)

If you want some information on moly.... here is a link for you:

http://www.snipercountry.com/hottips/Moly.htm


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## xdeano (Jan 14, 2005)

I agree with Plainsman...

I use a moly powder on the bullets, and use a liquid moly on the bore. If your going to do moly do both the bullets and the bore.

If you are just going to do moly bullets and not the bore, it will take several rounds to coat the barrel. It will also leave a bit of fowl in the barrel. for example the first shot throught a clean bore leaves a coat of moly the first few inches then it is down to the jacket and leaves fowl the rest of the the way, the second shot builds up more moly the first few inches and extends it maybe another few inches and fowls the rest again. So each shot buils up until it is completly coated.

JB paste works well for get all of the crud out.

Something that i've heard but i'm not sure if it is true or not, is that if you leave your rifle sit for long periods of time the moly acts like a moisture magnet and sucks water in, eventually rusting the barrel and the accuracy goes out the window.

As far as moly and H2O = Acid, I doubt that. But i will look into it.

Deano


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## xdeano (Jan 14, 2005)

Ok here is what is what with Molybdenum disulphide, or Molybenum sulphide, or Molybdenum (IV) Sulphide

Molybdenum - Mo, Atomic # 42, Atomic Weight 95.94, Melting Pt. 2375 *C

Sulphide S2

Molybdenum disulphide MoS2

Sulfuric Acid H2SO4, Molecular weight 98.0734

MoS2 + H2O can not = H2SO4

Reason:

Molybdenum is a transitional metal, the water acts as a base and the metal ligand bond is not strong enough to hold the O2. The H2o is in an Octahedral field which binds 4 sights, so 4 waters can bind but they cant hold together because the activation barrier can't be broken. It would take a lot of external energy for these two to bond and form sulfuric acid.

This Inorganic Chemistry, I hope this clears up a few thing. If there are any questions, please ask.

Deano


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