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jaguarxk120

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Discussion starter · #1 ·
I know that graphite is used to coat lead shot, but has anyone tried using
a moly coating?

The moly seems as if it would be a better lube on the lead shot.

I've read that some shooters will use moly on wads for better performance.
 
Pinewood derby article. http://www.maximum-velocity.com/lubesqa.htm

Thought this line was interesting-

"What about graphite with molybdenum (moly)?
Molybdenum is a hard metal that is used as a lube in some industrial processes which require a lubricant with no electrical conductivity, high pressure, and high heat. None of these conditions apply to pinewood derby racing. In our testing the addition of molybdenum to graphite did nothing for performance, but did scratch the axles that you just spent so much time polishing."
 
Referring to Hal4son comment.

Pretty sure lead was in gasoline to retard ignition of the fuel and therefore help prevent pre-ignition issues when the fuel was compressed in the piston stroke. That pre-ignition is heard as pinging on acceleration and was not good on many engine components. Also not good on valves and the valve seats due to them not being in their correct position before ignition occurred. That is why hardened valves and valve seats had to be made when the switch was made to unleaded gas. Tetraethyl lead also allowed for cheaper fuel that was of higher octane required by the engine designers. I have never heard about lead being there as a lubricant. I had as my first car a used 64 Impala SS that had a 327 cid engine. It really required Premium gas and would spark knock terribly with as little as $1 worth of Regular grade gas. Of course a $1 worth of "Regular" back then was almost 4 gallons! LOL

I have used both powdered graphite and Moly-D in shot and because you are using such a small amount; I don't think there is any issue possible. It takes very little of either to mix with shot.
 
jaguarxk120 said:
I know that graphite is used to coat lead shot, but has anyone tried using
a moly coating?

The moly seems as if it would be a better lube on the lead shot.

I've read that some shooters will use moly on wads for better performance.
Complete waste of time and effort to molly coat shot.
 
Also not good on valves and the valve seats due to them not being in their correct position before ignition occurred. That is why hardened valves and valve seats had to be made when the switch was made to unleaded gas.
If lead had only to do with preventing pre-ignition, then why weren't the valves closing properly when unleaded gas was being used?
 
Zbigniew I have answered your question via PM so as to not high jack the OP's thread any further.
 
Zbigniew said:
Also not good on valves and the valve seats due to them not being in their correct position before ignition occurred. That is why hardened valves and valve seats had to be made when the switch was made to unleaded gas.
If lead had only to do with preventing pre-ignition, then why weren't the valves closing properly when unleaded gas was being used?
Actually the valves closed just fine until seat wear caught up to the system, thus Hardened Valve Seats came into use.
 
Hal4son said:
Pinewood derby article. http://www.maximum-velocity.com/lubesqa.htm

Thought this line was interesting-

"What about graphite with molybdenum (moly)?
Molybdenum is a hard metal that is used as a lube in some industrial processes which require a lubricant with no electrical conductivity, high pressure, and high heat. None of these conditions apply to pinewood derby racing. In our testing the addition of molybdenum to graphite did nothing for performance, but did scratch the axles that you just spent so much time polishing."
We're not talking about the metal molybdenum, which actually does conduct electricity since it is a metal. We are talking about molybdenum disulfide which resembles molybdenum metal about as closely as iron resembles rust.
And, molybdenum disulfide is also really messy stuff that's very hard to wash off of your hands.
 
jaguarxk120 said:
Moly is a lube since the molecules of the moly slide on each other. Graphite is actually carbon
and a abrasive. Graphite does work as a lube but it is not in the same league as moly.
Graphite molecules also slide on each other, that's why graphite is such a good lube.

A drawing of a molybdenum disulfide crystal.
Image


Here is the arrangement of carbon atoms in a graphite crystal. Graphite is black, conducts electricity, and is one of the softest substances known.
Image


Notice any similarity in the crystal structure?

Rearrange the carbon atoms into this crystal structure and now it is the hardest substance known, becomes transparent, and no longer conducts electricity.
Image
 
Moly was used with rifle bullets for reasons that don't apply to shot from a shotgun. In recent decades, it has fallen out of favor with rifle reloaders. The claims made for it were not factual.

Eventually it was realized that all it does is coat the barrel with a thin amount of moly. When the rifle is fired, some of the energy of the powder vaporizes this moly, which then settles back on the barrel. Since this energy is diverted from accelerating the bullet, the bullet velocity is lower. If you wanted the same velocity, you had to use more powder. Claims that moly increased barrel life were simply due to the lower velocity, which always allows rifling to last longer. That does not apply to shotguns.
 
If velocity is what wears out rifling, then the greatest rifling erosion would be at the muzzle where the velocity is highest instead of the breech where the velocity is lowest.
Since most bench rest barrels lose their extreme accuracy due to throat erosion, I must assume it's the extreme heat of the burning powder gasses that erodes the rifling, and of course, the higher the velocity, the more powder is burning in the chamber so barrel wear and velocity are tied together even though it's not the velocity itself that erodes the barrel.
A lot of shot out barrels can be brought back by shortening the barrel at the breech end and then cutting a new chamber so the throat is like new again.

Muzzle loading rifles have a rifling wear at the muzzle problem due to wooden ramrods which embed grit wearing the rifling at the muzzle and often a "shot out" barrel can be brought back by cutting a few inches off the muzzle and recutting the crown.
Serious muzzle loading target shooters usually use stainless steel ramrods with muzzle guides so the ramrod never touches the bore.
 
The wear that destroys a rifle barrel occurs just forward of the chamber where the heat from the corrosion of the firing is at it's worst. It is not uncommon for bench rest shooters to rechamber a used barrel so that the chamber moves beyond the erosion thus extending the life. they can do this a number of times before they need a new barrel. Any wear at the muzzle is never an issue.
 
Yep, as they correctly noted,, rifle barrels "wear out" from throat erosion, literally melting the rifling out from the chamber forwards, not from the muzzle backwards.
This erosion is driven by HEAT, not velocity. A perfectly good, brand new barrel can be Shot Out in an afternoon of 3-4 HUNDRED rounds if you get the barrel hot (say, a prairie dog hunt) if you don't allow the barrel to cool. Many PD hunters will take 2, or 3, rifles with them.
The same barrel should last multiple thousands of rounds if it were never gotten really hot.
 
OldStufferA5#1911 said:
Yep, as they correctly noted,, rifle barrels "wear out" from throat erosion, literally melting the rifling out from the chamber forwards, not from the muzzle backwards.
This erosion is driven by HEAT, not velocity. A perfectly good, brand new barrel can be Shot Out in an afternoon of 3-4 HUNDRED rounds if you get the barrel hot (say, a prairie dog hunt) if you don't allow the barrel to cool. Many PD hunters will take 2, or 3, rifles with them.
The same barrel should last multiple thousands of rounds if it were never gotten really hot.
Sounds like a real good reason not to buy a bump stock for your AR. Of course, a lot of the AR shooters I see at a public range wouldn't know the difference if their barrels were shot out. They seem to be at the range to burn ammo, not to hit anything.
 
An educated finger works better and faster than a bump stock, but that takes time and effort to teach that finger.
 
I should have clarified that it is in fact "heat" (flame cutting) that wears out rifle barrels. This is directly proportional to pressure, which is always higher at the breech than the muzzle. That's why rifles wear out from the breech. If velocity is reduced, the pressure is lower throughout the barrel. That's all that moly does, except for wasting money.
 
IndyCA35 said:
I should have clarified that it is in fact "heat" (flame cutting) that wears out rifle barrels. This is directly proportional to pressure, which is always higher at the breech than the muzzle. That's why rifles wear out from the breech. If velocity is reduced, the pressure is lower throughout the barrel. That's all that moly does, except for wasting money.
My understanding is that the main purpose of nitro guanidine in triple base smokeless powders used in large bore artillery is to reduce flame temperature while maintaining chamber pressure in order to reduce barrel erosion in those guns. Even so, the Iowa class 16 inch guns only had a service life of about 290 rounds.
 
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