MOLLY Coated bullets cause of rust?

IDPACONVERT

IDPACONVERT

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It's a question that was raised by a couple of 5.56 shooters, these are coated for less friction, better accuracy ect.... but are they the culperate behind the little rust spots? Not from the MOLLY itself, but from the moisture it attracts.

Your .02 please
 
I don't know about rust, but better accuracy is not in play. At most the molly lets you clean less often by reducing copper build up, and reduces friction which in principle means higher velocity with lower chamber pressures.
 
From http://www.varmintal.com/arelo.htm

MOLY/WATER AND CORROSION.... I have performed a Moly/Water Slurry corrosion test on one of my Contender carbine barrels. The picture shows the etched spot on the underside of the barrel just forward of the forearm hanger. I sanded the bluing off of the area and placed the mixture on the spot and waited 1 day. The surface was etched and is rough to the touch. When I get a chance, I will try to measure the surface height with a dial indicator. I am not sure if I have the accuracy with my cheap indicator to do the job. You can test any barrel that you might be concerned about to see if there could be a problem. I would suggest that if you shoot Moly bullets in a regular Chrome-Moly (4140) steel barrel in wet weather, that you clean and oil the barrel the first chance you get. A similar test on my Encore 22-250 Imp/40° stainless steel barrel showed no corrosion attack at all.




CONDENSED MOISTURE.... I did another test to simulate a cold rifle being carried into a warm room. I took my piece of mild steel and machined a new surface and polished it. Then I put some powdered Moly on a piece of paper and rubbed the steel on the Moly powder until it was well coated. I took a cloth and wiped vigorously all the Moly off I could, but it was still well coated and shiny Moly. I left the piece of steel for one week and it stayed as shiny Moly as at first. No corrosion or attack of any kind. Next, I put the piece of steel in the freezer for 30 minute and than took it out and let it set in open air. A thin layer of moisture condensed on the steel. Two hours later it was etched where the Moly shiny surface was and also rust was present. (On earlier tests with the Moly/water slurry, there was NO rust. I suspect that there was sulfuric acid present that dissolved the iron oxide to form iron sulfate and no brown rust was evident at all.) So the condensed moisture on the Moly caused both etching and then it proceeded to rust the steel. There was not enough sulfuric acid IMHO to convert the rust to iron sulfate. (This is speculation.) Another very important part of the condensed moisture test was that the areas not coated by the Moly showed no rust or any other corrosion attack by the thin layer of moisture.

Remember, that if you have stainless steel barrels, there are none of these corrosion problems. In my book, it sure makes me want to buy only stainless steel barrels from now on, not only because they last longer, but because of their resistance to corrosion.

KROIL PROTECTS THE STEEL.... I performed another test. I used the same piece of mild steel and machined a fresh surface. I rubbed in the Moly and after a few hours, rubbed it with a cloth wetted with Kroil to simulate a cleaning patch going through the barrel. I rubbed it dry with a second cloth. I let this set for another few hours and then I put the steel in the freezer for 30 minutes and removed it to the room. Moisture condensed on the surface. The Kroil-treated Moly surface did NOT rust or etch. It appears that the Kroil prevents the condensed moisture from attacking the Moly/steel surface. This needs more testing, but it appears that cleaning a blued steel barrel with patch wet with Kroil would protect the barrel in cold or wet weather from the Moly/Water corrosion problems. There are probably other oils and cleaning agents that would also work as well as Kroil, but I had it available for testing. Also, the ammonia and the basic nature of Sweet's 7.62 would probably neutralize any acid effects of the Moly/Water combination.

FIVE POINTS TO CONSIDER.... Here are the five points that can be made about this set of crude experiments:

Point 1. Stainless steel (416) is not attacked, corroded, or etched with a mixture of Moly and tap water applied directly to an unprotected surface in 24 hours.

Point 2. If one has a stainless steel barrel and shoots Moly-coated bullets and shoots in wet or cold weather, there is probably not a corrosion concern with that barrel even though small amounts of water could come in contact with the Moly in the barrel.

Point 3. Chrome-Moly (4140) steel is attacked and etched with a mixture of Moly and tap water in as little time as one day and probably less. The etched surface is rough to the touch and is not a surface I would want in the bore of any of my rifle barrels.

Point 4. If one has a Chrome-Moly (4140) steel barrel and shoots Moly-coated bullets and shoots in cold or wet weather, there could be a problem with corrosion if moisture condenses on the Moly surface. If you have a concern, you can easily test your own barrel steel on a small area somewhere hidden on the bottom side to see if there is actually a corrosion problem.

Point 5. If you are shooting a Chrome-Moly (4140) steel barrel and Moly-coated bullets in cold and/or wet weather, you should clean and oil the barrel right after you return from the range.

I SHOOT MOLY-COATED BULLETS.... I shoot Moly-coated bullets and will continue to do so. They are great and shoot very well without cleaning after a few shots. This is very important in the small calibers like the 17's. I used to have to clean to preserve accuracy after 20 or so rounds, but can now, in most cases, shoot five times that many rounds before a noticeable reduction in accuracy occurs. I sure am going to clean and oil my blued steel barrel after shooting Moly bullets in wet or cold weather. I don't own any Moly stock and am not being paid by any Moly company, nor have I been given any free samples. I hope I am not frightening anyone into not using Moly-coated bullets. They work very well for me and I will continue to use them. If I help prevent someone from ruining a barrel by neglecting it after a wet weather hunt, then that is a plus. That's my payoff. Good Moly Bullets from Varmint Al.
 
reduces friction which in principle means higher velocity with lower chamber pressures.
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Reduced pressure and reduced friction, will reduce velocity. You may find you will need an extra .5 grain of powder to get the velocity back up.
I have been shooting Moly through SS barrels for about 8 years. In a resent experiment I went 900 rounds before I cleaned. I should have kept going. The rifle was shootin about 1/2 MOA all the way to 1000 yards, when I did my part.
After cleaning I didn't get this kind of accuracy back until and 200 rounds.
 
Reduced pressure and reduced friction, will reduce velocity. You may find you will need an extra .5 grain of powder to get the velocity back up.
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Agreed. But once you get back to the original velocity, the max (and average) pressure should be down from a non-molly bullet. Quickload shows a 1000 psi drop for a 69gr Sierra at 2814fps, comparing regular and molly bullets. It showed a .3gr increase in powder (RL15)
 
Once a centrefire rifle is fired, there are no preservatives left in the bore. The bore is fouled, unprotected steel. If you shoot moly, the bore is coated with MoS2. Even if moly is inert, it is not offering protection from corrosion. There are routines for light cleaning to preserve the moly coating. Complete de-moly cleaning takes serious cleaning, and the moly coat must be re-established for the rifle to settle down again. The QC tech at Sierra did an exhaustive test of moly using their bullet testing rail guns. He did not observe any enhanced accuracy or barrel life. This was based on thousands of rounds being fired through a number of barrels fired in an indoor range. Maynard's observations have been noted by other shooters, and this may be the biggest advantage of moly. By the same token, one of my US friends who won the Long Range Challenge at Connaught (15+2, four times, @ 900m.) did not use moly, and thoroughly scrubbed his rifle clean at the end of every day's shooting. Had not shot the CFRC before, but placed handily in all shoots.
Something to consider: the original NECO moly system applied wax over the moly. This would totally change things, because the combustion and decomposition of the wax would affect what builts up in the bore. As far as I am concerned, if you are going to use moly, just use moly, and nothing else. By the way, the use of noly lubes goes back at least 90years, when horrible cupronickel bullet jackets were the standard.
 
I tried the wax for a few batches of bullets. If you don't apply it just perfectly the bullets look so bad I would fire them from someone else's rifle(well maybe :mrgreen: )

I stopped using the wax and just roll the bullets in a rag to get the excess moly off.
I do clean the chamber, but don't touch the barrel.

Those that use moly, use it all the time. Others tried it, and don't bother with it any more. Even some of the guys shooting naked bullets are now going longer without cleaning.
Of course the people that tell you that you should clean every day or every so many rounds, are the people that make and sell the cleaning gear. :shock:
 
I have seen and read all kinds of stuff about this, including the article posted above, but it is always done with plates of steel or the outside of barrels. I have never seen or read about any bore actually being rusted as the result of using moly coated bullets. :?

I know several guys who shoot moly all the time, even in their hunting rifles, and have never encountered this problem.

Does anyone know of any real experience of rusted barrels, or is this all just conjecture?

Thanks,
Ted
 
Mostly it affects the bolts on the semi's & the gas system, I'm sorry but I haven't heard much about bolt guns, although I imagine that if you have a good cleaning decipline, it shouldn't be a problem.
 
I always hear about folks who either don't touch the stuff or who shoot strictly moly from certain barrels. Does anyone shoot both from a given rifle regularly? Is there a problem with going back and forth? I'm guessing that if it takes 200 rounds + to get accuracy up to snuff with the moly bullets then there is little advantage to shooting it infrequently.
 
I feel that my rifle took about 200 rounds to get back to where it was before I cleaned it. Now that is my feeling and not a general rule of thumb.
Some people said it takes 5 rounds some say 10-20 to settle back in.
A friend of mine shoots moly, cleans with Kroil and 5 stokes of a nylon brush and dry patches every night. He has 100% faith in his first sighters.
I don't know of anyone that switches back and forth between naked and moly bullets.
 
I moly all my bullets and have two stainless and two chrome moly barrels... no issues with corrosion at all in six years.
I get very good consistency regardless of cold/hot or fouled/non-fouled barrels :?
 
Slash 5's test is a good start but it needs to have a slurry of something else and water applied to a barrel also... Say cornstarch and water. Or just a clean damp rag applied to hold the water in the same way for the same time.

Because without those "controls" you have no way of knowing if moly actually has any affect on corrosion other than to possibly hold some moisture. We all know water alone will corrode steel.
 
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