Question about bullet lube physics.

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chris in va

New member
I tumble lube exclusively and haven't used any with the wax in the band(s).

Now, how does the first half of the bullet get lubed if the ring is in the last half of the bearing surface? Plus I've seen a lot of fired bullets with the wax still intact in the band.:confused:
 
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snuffy

New member
Chris, that's a very good question. One that has only one good answer. The first boolit that gets fired,(from a clean barrel), should have some bullet lube on the ogive to help it slide down the barrel. The rest of the boolits will leave a trace behind them for the next one down the pipe. Another way is to treat the last patch used when cleaning with some bullet lube, then pass it down the barrel.

As for the physics of how the lube works, that's been an argument for years. There's as many opinions as there are different types of lube. Take a look at the castboolits site here;

http://www.castboolits.gunloads.com/forumdisplay.php?s=&daysprune=&f=58

Try a search for lube theories, or just look at the threads and read ones that look like the right info.
 
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Elkins45

New member
Bullet lube is almost as much art and voodoo as it is chemistry and physics. You could spend hours reading all the info on lube on the Case Boolets forum and still not have a real grasp of it. Believe me, I know this from firsthand experience!

About your question: The lube leaves a bit of a film that coats the bore for subsequent rounds. Only the first one down a clean barrel has much direct lead to steel contact. But you're thinking that bullet lube prevents leading primarily by creating a slick surface...there's a school of thought that says one of the mechanisms of leading prevention is helping to seal the bore so lead doesn't get melted by hot gas blow by. This is at least partially supported by the experience of a lot of shooters who get terrible leading with undersized bullets regardless of how hard or well lubricated they are. This is because the gasses blow around the poorly sealed base and melt the bullet through flame cutting effects. Properly sized but softer bullets show less leading than harder ones that are too small for the bore. It is theorized that good lubes help with proper obturation.

About the bullets with lube still in the groove: a lot of commercial lubes are chosen for their ability to resist handling and still stay in the grooves rather than for their performance qualities. It's hard to market cast bullets that are gooey with half the lube missing from the grooves. That red or blue stuff that a lot of commercial cast bullets are lubed with hangs in the grooves very well but isn't all that great as a lube...but it can withstand shipping and handling well.
 
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PawPaw

New member
Elkins45 said:
That red or blue stuff that a lot of commercial cast bullets are lubed with hangs in the grooves very well but isn't all that great as a lube...but it can withstand shipping and handling well.
Click to expand...

Yup, I've recovered bullets from a berm with that lube still in the grooves. It sticks to the bullet very well. That makes me wonder how much of it was actually used in the trip down the barrel.

Actually, the vast majority of cast bullets are fired at velocities under 1000 fps. I'm talking pistol bullets here, but probably 99% of all cast bullets made are shot very slow velocities. At those velocities, any lube will do. I've even finger-smeared hog lard on bullets and they shot just fine. Nowadays, I tumble-lube all my cast bullets. Pistol bullets get one coat, high-speed bullets that need a gas check get two coats. Once before and once after installing the check.
 
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totaldla

New member
I'm in the "seals the bore" camp. I don't believe that lube does much of anything to reduce the lead on steel friction. A bore "seasons" after a few shots and will stop accumulating lead. Usually a "seasoned" bore is the most accurate.
 
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Ideal Tool

Moderator
Hello, Chris in va. There is a theory that some of the "young gas" blown by the bullet before it can obturate & seal the throat carries a small amount of lube with it past bullet. Just a theory though. Quite a lot of information over on the Cast Bullet Association forum.
Concerning lubes..some of the sliperiest concoctions were found to be less accurate. Another thought is that bullet lube acts as an anti-flux to prevent leading.
 
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