Maybe it's counter-intuitive and I just can't fathom it. Somebody please help me understand.

People say that moly lube is too slippery to allow the bullet to attain the velocity than a similar bullet with conventional lube. When Teflon coated bullets came out years ago they were considered dangerous to law enforcement because they could penetrate body armor of the day. This tells me that the Teflon bullets attain a higher velocity because of the lubricity of the TFE. Is this correct?

Ok. Now moly. People say that it gets out of the barrel too fast to attain max pressure and complete powder burn. If it's leaving the barrel too fast, wouldn't it mean that the velocity is already higher at that point than with conventional lube?

Does anybody have hard facts aside from what's been read or said, like an analysis with a chronograph done with enough proper protocols to give dependable results?

If that can be confirmed, does anybody have an explanation that overrides the basic sense that a bullet that leaves the barrel so fast that it doesn't have time to properly burn and attain max pressure and velocity is already going faster than a conventional bullet/lube?

It's conceivable that a bullet could travel faster down the barrel than a powder/combination is designed for, but again, if it's going that fast, it's already traveling faster than a conventional load. MAYBE the bullet goes very fast in the first part of the barrel, then slows down drastically before leaving the muzzle. It's also conceivable that, at least in firearms, moly isn't a very good lube for some reason. (heat, pressure, viscosity??)

There may be some other factor that can account for any difference in velocity. Can anybody pin this down?

There are many problems with moly and it has fallen out of favor but I would just like that question about lower velocity answered.

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"He was kinda funny lookin'"

I had some Lapua 6.5x55 ammo and since this was about the time the moly craze was in full swing decided to try something. At the junction of the case neck where the bullet was seated I put a small amount of moly paste around the bullet at that location. Velocity increase was exactly 25 feet per second. After I had satisfied myself that maybe there was something to be gained I discontinued it. In the now defunct magazine Precision Shooting there was an article regarding loading the 155 grain sierra palma bullet. Seems you had to load this bullet fairly hot and hot weather compounded the problem. It was found that moly coating gave increased velocities but with lower pressures. Sometimes accuracy fell off due to this so the answer to that problem was more powder to get the accuracy back. Sort of a dog chasing it's tail kind of thing. There are a bunch of moly products on the market. 3M markets moly assembly paste, powdered moly and so forth. I gave away some of the powdered moly to a friend who made a cast bullet lube with it. Like the old cast iron frying pans he found that the barrel had to be seasoned with it to get good accuracy. Now its rare that you hear anyone even mentioning it. Frank

Part of the problem here is that you are taking Mainstream Media headlines and presuming they have some relationship to real fact.

The alleged advantage that a PTFE coated projectile has when hitting "SOFT" body armor is that the teflon helped the projectile slide through the layers of Kevlar. Velocity was not a player in actual penetration.

Maybe it's like a car that cuts a great 60' time? They will reach the end of the quarter faster, but usually have a lower MPH at the end. Only analogy I can think of that is along the lines of what you are saying. I know nothing about moly bullets. A bullet accelerates over a fixed distance too, though.

Basically a car on say drag radials can accelerate harder at the start. That pays dividends the entire track, and they reach the end sooner. Because they got their sooner, they had less time to accelerate.

Well when you find a load/bullet for a handgun that accelerates on the way to the target let me know. All mine start slowing down when they leave the barrel. Now that would be a flat shooter.

Don

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USN Retired/VN VET
M&P X5

My only experience is what I have read. There are lots of those who swear by moly, and those who swear at moly. Most claim that it will slowly coat the inside of your barrel with moly. Many proponents say you must shoot only moly once you switch. Many of the detractors say that cleaning becomes problematical.

The fact that moly coatings have fallen out of favor speaks volumes to me.

People make much out of small difference. people extrapolate into stratospheric arenas of the ridiculous. People talk authoratativly about things they know almost nothing about. Does a teflon coating make a difference? Sometimes, a small but measurable difference. Does a moly coating make a
difference? Yes, sometimes there is a demonstrable ballistic difference. Is it highly advantageous or disadvantageous? No.

Not even going to the controversy/hype over nylon clad or moly.

Just like the ATF wanting to ban 556 ammo.

Moly was a fad that soon died out real quick. Problem with moly is it is the most tenacious stuff to remove.

Once it coats everything it is very hard to remove.

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Still Running Against the Wind

I've avoided moly due to the tenacious nature it has.

The prospect of cleaning it out of a firearm never appealed to me.

Sounds like the paradox is clearing up nicely

Mike

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NRA Certified Pistol Inst.

Your post made me think of the Gyrojet pistol.

One factor I rarely hear mentioned in these equations is the shot-start pressure. If it's the same for each round then you'd have a fair comparison, but achieving that isn't easy, especially with brass that's been fired a few times. Neck tension (which controls shot-start pressure, along with crimp) is pretty hard to quantify, but if you want a better powder burn, you generally need more neck tension.

Once the neck tension question is addressed, then you could do a fair comparison between moly-coated bullets, jacketed slugs, plain lead bullets and powder-coated ones. I got over the "velocity disease" a couple decades ago, now I just want all the accuracy I can get. But then, I don't hunt and the longest distance I can shoot is 100 yards. If I was out to spank a 5x5 Elk or shoot at 600 yards, velocity would naturally be a bigger concern. But the elk still couldn't tell you the difference between 2400 fps and 2800!

At least to me, this makes perfect sense. Just the kind of info I was looking for. Thanks.

PS: And I'm way past wanting to use moly. But this always bothered me and it did come up recently on another thread. THANK YOU.

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"He was kinda funny lookin'"

I appreciate the info, but the nature of thead should indicate that I don't take ANYTHING to be fact without good reason. I simply didn't really know about the TFE bullets. It was a long time ago. Thank for clearing that up for me.

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"He was kinda funny lookin'"

My example was stated to be within the barrel only. I really didn't anticipated a bullet to accelerate after the muzzle, except for maybe some slight effect of gas expansion at the crown.

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"He was kinda funny lookin'"

The stuff's no good. The only thing that bothers me is people saying that their velocities were lower when it was used. Unless the reason could be that in a firearm for some reason it's a lousy lubricant and actually slows the bullet down.

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"He was kinda funny lookin'"

I really like Frank46s explanation.

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"He was kinda funny lookin'"

I was wondering if there weren't other reasons to explain possible velocity loss and these are some plausible explanations. I think that only a highly controlled experiment would really answer the questions. Max velocity isn't important to me either, but the velocity paradox really rubs my sense of wanting to know the real story the wrong way. I have no other interest in this outside of why it is said that using moly results in lower velocities.

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"He was kinda funny lookin'"

Maybe I should clarify something about the 6.5x55 cartridges and the moly I put on. I had a small artists brush and since the moly paste I used was fairly viscous just painted a band on the bullet just above the junction of the case neck and bullet. Upon firing any moly that remained on the case was gone. Most likely blown into the barrel when the cartridge was fired. The lapua bullets did not have a coating on the entire bullet. Fairly simple using the brush to apply the moly that way. Little to no moly was noted being found in the chamber. maybe that makes more sense. Frank

There is a really good book that covers many of the subjects mentioned in this thread. It's called "Hatcher's Notebook" by Julian S. Hatcher, Major General, USA, retired. It was last revised in January, 1962, and General Hatcher has long since passed away. I have recently re-read this book and I am still amazed at the detailed information enclosed. The book is still available on Amazon.

If you hold the pistol sideways and push the gun towards the target, as you fire, not only will the bullet accelerate towards the target but you will never run out of ammo in your gun.
Must be true because I see that shooting style on TV.

Yes and I read that on the internet also and watched a video also. Darn how did I miss that. Don

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USN Retired/VN VET
M&P X5

The Teflon thing was to allow the bullet to penetrate hard surfaces better, not to make it go faster. As the bullet hits a surface it generates heat, heat is energy loss, so the Teflon reduced that. No coating in itself gives higher vel. I noted this before; pressure = vel, all other things being equal. A slicker bullet won't be faster, it will be slightly slower.
I bought some CT 160gr bullets, moly coated. Didn't care for the moly, made switching back to gilding metal diff, So I tumbled it off. With the same load, the vel was higher with the moly coating tumbled off. Without pressure testing, hard to prove this, but Barnes shows sim results with there same profile bullets moly coated. IMO, the bullet leaving the bbl too fast might be over simplifying what I am saying, less pressure = less vel.

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NRA Cert. Inst. IDPA CSO

Teflon defeating armor is a complete load of bull.
The function of Teflon in AP is to protect the bore from the ridiculously hard bullet materials.

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it just needs more voltage

The teflon bullet thingy was the Remington Accelerator sabot bullets that let you shoot .223 bullets in a .308 and get 3000 fps or a 30-06 and get nearly 4000 fps. You can still buy those sabots, but not the loaded ammo. There are other rifle cartridges that let you shoot those speeds nowadays anyways.

Moly coated bullets will reduce the MV by about 5 fps in a 5" pistol barrel and about 10 fps in a rifle barrel. That's because it takes slightly less force to engrave the rifling and drive the bullet down the barrel. That leads to the bullet starting down the barrel quicker, but allowing the expanding gases to build up less pressure because the volume behind the bullet is larger than with a slower moving bullet. Just the opposite of trying to drive a heavier bullet with more inertia.

The difference in muzzle velocities is negligible and most likely not much more than the variations between shots in a test string.

and it just gets muddier

The remington accelerator has nothing to do with teflon.
that was polyethylene.

This is the world famous teflon coated cop killer bullet of lore.


manufactured for law enforcement, by KTW. these are loaded with lathe turned bronze and tungsten alloy projectiles that'd turn a barrel into a smooth bore in a few mags.
the sole purpose of the teflon was to protect the gun from the ravages of these materials.

Further reading
Teflon-coated bullet - Wikipedia, the free encyclopedia

really ... think about it.
Teflon is a rather soft plastic whose only claims to fame are heat and chemical resistance and inherent lubricity.
it's not magic folks.
Teflon was only the ducktape that made something else work

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it just needs more voltage

>People say that moly lube is too slippery to allow the bullet to attain the velocity than a similar bullet with conventional lube.
Wrong. I have NEVER, in 40 years of reloading, read any real scientific data on why jacketed, plated, cast, and coated bullets perform the way they do. You can load to the same pressure, and, in general, the jacketed will take a higher charge to reach that pressure and will often attain a greater velocity (which could make some sense with more powder gasses behind it). It would take someone in the lab, doing work that wouldn't pay for itself, to come to any read reasons.
>When Teflon coated bullets came out years ago they were considered dangerous to law enforcement because they could penetrate body armor of the day.
And, that is another lie from the left. All the Teflon was doing was lubricating the bullet and had NOTHING to do with penetration.
This tells me that the Teflon bullets attain a higher velocity because of the lubricity of the TFE. Maybe?
Ok. Now moly. People say that it gets out of the barrel too fast to attain max pressure and complete powder burn.
Max pressure is achieved while the bullet is just reaching the forcing cone/throat. It is not some long delayed thing that occurs with the bullet down the barrel (where, pressures are in fact dropping off).
>If it's leaving the barrel too fast, wouldn't it mean that the velocity is already higher at that point than with conventional lube?
Yeah, if the statement made any sense.

I think I cleared up the role of teflon in AP in a previous installment.
I'll toss one of my tests in your general direction though, as this is something of an anomaly.

before I played with Hy Tek coatings, I ran entirely with powder coatings.
One of those powder coatings was in fact, Teflon.
I had cast a continuous run of 2000 200gr 45 HP's from a custom mold. The lead alloy was uniform through this entire run.
I split this run in half, coating 1000 in a standard issue powder coating and another 1000 in the teflon.

I then took 250 from each half and mixed them for a 500 round continuous run in new starline brass.
Powder and primer lots also the same as well.

charge set, whatever bullet came from the bin of glory went into the case.
after the run was complete, the standard and Teflon versions were separated for range testing.

the funny thing is that the Teflon fired over the chrono produced an extra 40 FPS and a slightly higher SD.

Where the friction/volume/pressure relationship makes perfect sense, where did the extra 40 come from?

I wonder if the teflon acted the same as standard till the pressure peaked, then "kicked in".

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it just needs more voltage