What happens to the lube on a cast lead bullet when fired...Does it vaporize before leaving the bbl, melt some and travel with the bullet, break up and make those greasy specks on a close in target, burn up and cause the sooty smoke......I'd like to know.......Thanks...2#

I think all of the above is the answer.

Typically when the bullet hits the rifling some of it gets squished out and should lubricate the barrel as it travels through but some of it depending on the lube and other factors gets burned up causing smoke. If you find lube on the muzzle of the barrel after firing it means the lube made it the full length of the barrel. I'm sure some other casters can elaborate more on the subject.

I pick D: all of the above.

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Still Running Against the Wind

It depends on several things, pressure, velocity, twist rate, and lubricant type, but overall the best answer is "D", all of the above. Much of the lubricant stays with the bullet until it comes to rest.

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Gunsmithing since 1961

The truth is, no one has definitively answered this question. Something I've been curious about too. There are long, elaborately-argued points of view about this at cast boolits, and the RKIs there don't REALLY know.

after picking slugs out of a dirt back stop the hard blue stuff seems to stay in the lube groove. 50/50 alox bees wax seems to go up in smoke. I have found lube on targets at 25 yards using the Lyman Orange.

Ted

Lyman Super moly will come off between the case and the 50 yard target as does a good home made version. [Felix] I want lube to have no adverse effects to accuracy in the bbl, not disturb rotation if it spins off in flight and prevent leading last. If the temperatures are between 45F and 85 F I should get a lube star at the muzzle from 20 rounds. That tells me most of the lube is being used in the bbl where I want it to be used.

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Front sight and squeeze

I believe most of it is thrown out of the grease grooves as the bullet leaves the muzzle due to centrifugal force from the spinning bullet. A very little may burn, but as the residence time of the bullet in the barrel is so brief, there is not enough time for much of that to happen.

I don't know about anyone else, but I have scavenged lots of lead bullets fron the backstop berm, and have never seen a fired lead bullet with any lubricant remaining in the grease grooves.

Pull them all the time with the hard blue stuff from store bought cast slugs.

It always depends on the lube used & the vel fired. I have recovered bulelts with no lube & bullets w/ full grooves. In handgun rounds, all are mroe accurate than most shooters could shoot. You want the lube to make it at least to the end of the bbl, after that, accuracy tells the story.

Mostly carnauba wax based lube seems to stick to the bullet and will stay on even when the bullet hits the dirt. Those are the only ones I find that still have any lube on them.

It seems to enter the "time space continuum" The faster the bullet goes the closer to the speed of light it reaches and it falls to the E=MC2 equation.

Time and the bullet will stop,and become one.

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Still Running Against the Wind

Are you Doctor Who???

Step into my TARDIS

When they had it as a regular series(the original not the new version) on PBS I watched it all the time, Great stuff!

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Still Running Against the Wind

It's been my experience that most of it lodges in my seating and crimping dies

On a zero degree day some of it goes through the front screen of your chronograph.....

How come I never see any lube on the target?

In short barreled pistols and revolvers? Not really. I've captured several fired cast bullets from both 9mm and 357's and pretty much all the lube was still in the grove. I think in a cast bullet shot at high velocity out of a rifle length barrel there would be enough heat generated through friction that a good amount of it would melt as it is forced down the barrel.

Actually,the lube's job is not exactly to lubricate but acts more like a gasket.The centrifugical force caused by the rapid rotation of the bullet in the barrel causes the lube to seal any space between the bullet and the barrel thus keeping the gases behind the bullet.If any of these gases,pushed at pressure from aprox 10K#/sq.in.in a .38spl target load all the way up to aprox 40K pressure in the trio of magnums would find a passage between the barrel and bullet,they would erode the lead and cause leading in the barrel.
Like DWALT said,some of it might burn and most of it is leaving the bullet as soon as the bullet leaves the barrel because of the centrifugical force.
You might also find some still clinging onto the bullet after it is recovered.It depends on the composition of the lube.
Qc

If you try many lubes and loads, you may eventually find lube residue even on 100 yard targets. After more than forty years of casting, sizing, lubing, and shooting rifle and handguns, I've gotten to the point where I use only two lubes, both commercial: a half & half lube and LBT Soft (which isn't real soft, but it's softer than a hard lube). I've tried many hard lubes for rifle and handgun bullets and I've never been able to tell that they offer any advantage over the two mentioned.

Bullet fit remains far more important than lube anyway.

5 year old thread resurrected.

That being said, I don't think anyone can say with certainty what goes on in the barrel of a firearm. The heat and pressures are just too great.

All we know for sure, is what went in one end, and what came out the other.

The rest is interpolation, and conjecture. Theory. Nothing I know of can be proven.

Qcpistolero, your definition of bullet lube asking as a gasket is exactly what I was told years ago when buying a bullet mold. While certainly there is lubrication going on aka lube stars at the muzzle, the sealing of the hot gasses behind the bullet is extremely important as when the gas escapes between the bore and bullet then leading and gas cutting occurs. Cannot remember his name but did business in Scappose Oregon so that may ring a bell. Frank

An excellent article on bullet lube and what it actually does along with what forces are acting upon the lube.

Lubricating Cast Bullets. Bullet lube does more than you thought

I've showed this picture before, it saw sent to my by a member on another website. We were discussing grease grooves and lube groove compression with round vs square lube grooves.


As you can see the lube grooves are compressed compared to the un-fired bullets above the recovered ones in the lines below.

It gets absorbed into the skin. Be sure to re-apply as necessary.

Oh, you were talking about bullets...

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an actual conservative

Bullet lube - its part of that funky smell at the indoor shooting club.

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DRB #2276

I read the article. It is very interesting indeed !

It does a great job of presenting a logical theory. He backs up his theory with presentation of what went into the barrel, what came out of the barrel, and what was left behind in the barrel.

It makes great sense. And, it may be what is happening in the barrel. But we don't know.

We don't know, because he presents no proof. There is no way we can "see" what is going on in the barrel as it is being fired. The pressure and heat is too much for present technology.

As for the lube-grooves being compressed - were the grooves compressed by the force pushing the bullet from the rear as it was fired?

Or, were the grooves compressed from the bullet stopping suddenly, and the rear of the bullet piling into the stationary front, when it hit whatever it hit ?

It looks very much like those bullets hit something, as evidenced by the distorted noses.

Ballistics is a very difficult "science", because Ballisticians really cannot prove what has happened. They can theorize, and use that theory until something comes along to disprove it (as all science is supposed to be done), but proof is very difficult.

You're flinching and closing your eyes!

Very simple physics, all of the above depending on lube and quantity used, caliber, combustion. There are some great mysteries in life, (like what were you thinking?) or conversely and more complex?? (what is she thinking), but this is NOT one of them.

If you're losing sleep over this????

If it's properly working , after firing look at the muzzle and you should see a lube "star" , a light deposit that resembles a star. If no lube star is present , then the lube is staying in the lube groove ( I've picked up plenty of bullets with hard lube still in the groove) or the lube has run out before exiting the barrel...not enough for the job at hand.
And of course some vaporizes into, my favorite TV show..." GUNSMOKE".
Gary

I am an active USPSA and IDPA shooter and handloader. It is quite common to find pieces of hard lube stuck to cardboard targets when scoring. Happens primarily with subsonic ammo like 45 ACP.

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Bob.
SWCA 1821

If you ever are around long enough to test your own lubes & alloys for a specific bullet/powder/firearm combo. You would have a very different real world take on what you read.

I'm not talking 50 or 100 test rounds. I'm talking 1000's of the same bullet/powder/firearm combo over decades of testing/shooting.

Some see theory because they don't have enough knowledge/experience to know any difference.

The only thing I know for SURE is that some of it is vaporized.
I have loaded the exact same load with a jacketed and a cast bullet and the cast/lubed bullet produced at least 3 times as much smoke.
This was to test the supposed "smokiness" of Unique powder and they were shot in the same gun.
The jacketed load produced very little smoke.
If I recall they were 240 grain bullets, 7 grains Unique in a 44 special.
Lube was more than likely a hard one as the cast bullets were commercial, either Oregon Trail or Beartooth.

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NEMO
"Everything 44"

"what is she thinking" ????????

NO Man has ever figured out that one.........

And some see evidence in support of a theory for exactly what it is : evidence in support of a theory.

Face it, if anybody had proof of what was happening, they would say something like this -
" Here is my video/photo showing the lube inside the barrel doing 'X' "

or-

"Here is my pressure graph from inside the barrel, showing the instant that the lube does 'Y' inside the barrel."

That proof simply does not exist.

Just because the proof doesn't exist does not mean that your favorite theory isn't true, it just means you can't prove it. As I stated about the LASC article, it is a very logical theory. He does show evidence to support it. It sounds good, and may very well be what is happening.

It's just that proof is lacking. Which is why it's a theory.

And, notice I did that without calling into question anyone's knowledge, or experience.

I'm dropping out of this science class.

In support of DumpStick... much cast bullet lore is based on "conventional wisdom" that some consider to be fact. Sometimes, maybe more often than we'd like to admit, the "conventional wisdom" even as it becomes "fact" is flawed because it has never been proven.

We still can't agree as to the complete function of bullet lubricant.

If you say so. I'm not going to banter about any article on lubes. It isn't my favorite article by any means. And as far as I can tell it's put bullet lube into a perspective that no one else as come close to in this thread.

I've found that people tend to take the easiest path when trying to understand something. This thread is no different. I'm glad to see you want what you consider proof, hence someone else has to do the leg work and provide you with a video.

I got an idear, why don't try to prove/dis-prove something yourself????

It don't take no Bodie rocket science, but it does take someone that has the ability to not only test bullets/lubes/loads. They have to have the ability to understand not only what they are actually testing. They need to understand the results they have from their testing.

Some people play checkers, others play chess. The people that play checkers tend to use google & the people that play chess tend to use the actual tools, parts & do actual testing.

With respect Forrest r, it seems that you and I are not communicating along the same lines.

Good day, sir.

Well the air in here seems to be getting a little thick.
I am moving over to using powder coated and plated bullets!

As our preferred system to investigate and hopefully explain the unknown, science many times generates as many or more questions than it answers.
I am of the opinion that this is for the best.
How bored would we be if there were no questions?
Only tyranny prefers such a state of affairs.
Long live confusion!

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NEMO
"Everything 44"