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View Full Version : How does lube from a lube groove migrate to barrel bore when shot??



Tallbald
06-08-2015, 10:38 PM
OK. I'll reinforce that I'm still very new to cast bullets by asking a deceptively simple question.
Say you have a bullet with one lube groove between two drive bands. A .358 SWC slug comes to mind. Cartridge fires, slug moves down the bore. Lube melts and lubes the drive band behind the lube groove. I suppose the front drive band goes lubeless(?) all the way down the barrel.
Now take a tumble lubed slug. Same SWC in .358 diameter. Both drive bands are coated with TL. Provided I used the good TL material, cartridge fires and the slug moves down the barrel lubed all the way if there's enough TL on the slug.
What am I missing? TL seems the best option to me.
Don

superdan
06-08-2015, 10:52 PM
http://www.lasc.us/Fryxell_Book_Chapter_5_Lubrication.htm

Frank46
06-08-2015, 11:30 PM
I once had the opportunity to speak to Walt Melander the founder of NEI bullet molds. He told me that lube was to act like a gasket to prevent gas cutting of the bullet while it went down the barrel. And to lubricate its passage down the barrel. Now to confuse you even further there have been posts where an experimenter has reported that shooting cast bullets without any lube at all, and done so without any leading. Frank

Tallbald
06-08-2015, 11:33 PM
Yes it is a thought-provoking topic for a shallow mind as mine. I TL exclusively, load for slow and accurate, and right now don't anticipate lubing other ways. Of course six months ago I didn't think I'd ever switch to an electric melt pot either......Don.

longbow
06-08-2015, 11:41 PM
Don't forget blow by and centrifugal force are both at work to displace lube.

Watch a slow motion video of a bullet leaving a barrel and there is always gas leaving first. If nowhere else, there is some blow by in the throat and centrifugal force is constantly flinging lube outwards.

Not to mention the boolits do get shorter when the trigger is pulled so there is pumping as well.

And intrusion of the lands into the lube reservoir also displaces lube.

If the bore was absolutely lube free and there was no blow by at all you might send that first round up the bore with a lubeless front driving band but it is not being compressed by the gas like the base driving band anyway so I doubt it would be an issue. Since I have not heard of a problem this way, I suspect it is not an issue.

Yeah, rereading Glen's article, I'll shut up now as Glen says it better than I can.

Longbow

Tallbald
06-09-2015, 12:14 AM
So the TL is not displaced but rather provides a barrier between slug and bore until it's stripped away along the length of the bore(?). Sounds logical. And the extra details of the lube migration are very interesting. Thank you all. I love learning. And appreciate the teachers. Don.

Mal Paso
06-09-2015, 12:28 AM
Don't forget blow by and centrifugal force are both at work to displace lube.

Watch a slow motion video of a bullet leaving a barrel and there is always gas leaving first. If nowhere else, there is some blow by in the throat and centrifugal force is constantly flinging lube outwards.

Not to mention the boolits do get shorter when the trigger is pulled so there is pumping as well.

And intrusion of the lands into the lube reservoir also displaces lube.

If the bore was absolutely lube free and there was no blow by at all you might send that first round up the bore with a lubeless front driving band but it is not being compressed by the gas like the base driving band anyway so I doubt it would be an issue. Since I have not heard of a problem this way, I suspect it is not an issue.

Yeah, rereading Glen's article, I'll shut up now as Glen says it better than I can.

Longbow

Everything he said plus whatever else you can think of.:grin:

I use a lubesizer with Glen's lube and have no leading issues with plane base bullets to 1500 fps.

My issues with tumble lube is unless you wipe the nose the lube finds every bit of dust and lint. If you want to go fast, it's hard to coat thick enough for magnum velocities and the TL style bullets have more of a tendency to strip rifling at high speeds.

Hang Fire
06-09-2015, 01:04 AM
Don't forget blow by and centrifugal force are both at work to displace lube.

Watch a slow motion video of a bullet leaving a barrel and there is always gas leaving first. If nowhere else, there is some blow by in the throat and centrifugal force is constantly flinging lube outwards.

Not to mention the boolits do get shorter when the trigger is pulled so there is pumping as well.

And intrusion of the lands into the lube reservoir also displaces lube.

If the bore was absolutely lube free and there was no blow by at all you might send that first round up the bore with a lubeless front driving band but it is not being compressed by the gas like the base driving band anyway so I doubt it would be an issue. Since I have not heard of a problem this way, I suspect it is not an issue.

Yeah, rereading Glen's article, I'll shut up now as Glen says it better than I can.

Longbow

True, when boolit compresses in the bore, hydraulics come into play.

44man
06-09-2015, 08:45 AM
My revolver boolits are .0005" under throat size and there is lube driving force from the gas right there. I get lube on the outside of the brass as well as some driven forward. My .44 has even more space with my .431" boolit in .4324" throats and the brass gets much more lube on it.
Then when I lube, there is always some on the rest of the boolit to start. I keep rounds in MTM boxes, not my pockets.
The cleanest gun I shoot is my BFR 45-70, brass does not need cleaned at all. With Felix I run 1630 fps with no leading at all.
Felix works in my 30-30 marlin too at over 1900 fps.
Glen brings up a point about hard lube found in recovered boolits, usually in spots that will throw a boolit out of balance. My recovered boolits are clean of all lube. I want all to spin off at exit.
I will always not see the lube acting like a gasket with the extreme pressures, Fit and a base seal should stop gas. Sorry, if gas leaks, lube will not stop it and you will cut lead. If it can cut lead, what chance does lube have of sealing anything?
Experiments with TL have been sad with leading and lube gone before the end of the barrel. I shoot the RD 265, TL, lubed with Felix and it is one of my most accurate boolits in the .44. If I hold right it will hold 3/4" at 50 and 1-1/4" at 100.
Most of my revolvers have not had the bores cleaned in 3 years with no loss of accuracy although I maintain clean and lubed cylinders.
I think Alox burns in the bore and leaves ash. It works better tempered with beeswax. Clouds of smoke from the muzzle is not good. Not powder smell, the stink of burnt Alox.
Another thing I found is a boolit skid at the front does no harm and might allow more lube pump but the skid MUST stop at the base. As long as the base seals, there will be no gas leakage at the front skidding.
More then one lube groove is better and all my boolits have 2 to 3. I think the 1 huge groove of the Keith harms balance and CG.
Then the ogive of the Keith has no steerage at the cone since the nose is smaller then the bore, BORE, let alone grooves so you depend on the little shoulder to steer the cylinder.
I have different opinions but they work for me.

Mal Paso
06-09-2015, 10:22 AM
[QUOTE= I get lube on the outside of the brass as well as some driven forward. [/QUOTE]

Totally forgot about that. At magnum pressures lube gets blown into the cylinder bearing, under the crane, as well as leaving a star on the muzzle. Lube gets where it needs to go if it's soft enough. Had some store bought bullets that the Blue Lube was so hard it was still on the bullets recovered in the berm.

AggieEE
06-09-2015, 10:44 AM
Years ago Guns & Ammo had a front cover shot of a lead .44 mag bullet right as it left the muzzle. There was lube on the ogive of the bullet. They used a thin wire as the trigger for the strobe. What I found interesting was the wire was bent to match the curve of the bullet.

44man
06-09-2015, 12:41 PM
I don't have explanations but it just plumb works as is. Go with the flow ( no pun intended!)
I have not tried PC and might never. I still feel lube will keep residue soft so the next shot will clear the bore. I have no use for dry fouling.
Had a huge problem with SPG in my BPCR where the last 10" was fouled so dry I could not patch unless the patch was soaking wet. No lube ring at the muzzle. I could not give away the rest at shoots, nobody wanted it. The best shooters in the country shot at my club and one took the nationals more times then once. He giggled at me.
Testing lubes showed me how vital they are for accuracy. Lube should be tested just like powder charges. Just because you have a pretty color does not mean much.

9.3X62AL
06-09-2015, 01:27 PM
I defer to the GREAT writing of Glen Fryxell above, and to Walt Melander's text on the subject also. Social science majors (like me, for example) should rightfully fear to tread on ground so well covered and understood by real scientists.

Having my very limited hard-science background in mind, I keep it simple......most of my pistol bullet lubricating gets done with NRA Formula 50/50 BW/Alox......most of my rifle bullet lubing is done by Lars' Carnauba Red.

44man
06-09-2015, 02:02 PM
Having my very limited hard-science background in mind, I keep it simple......most of my pistol bullet lubricating gets done with NRA Formula 50/50 BW/Alox......most of my rifle bullet lubing is done by Lars' Carnauba Red. "Quote"
Both work and I used 50-50 for a long time and Glen makes great lubes. CR has worked in my revolvers too. But I will never TL again.

gwpercle
06-09-2015, 05:24 PM
It just does. Sometimes you just have to accept things on faith.
If you don't believe me, just shoot a few with no lube in that groove.

My explanation........It's MAGIC !

Maximumbob54
06-09-2015, 05:39 PM
Keep in mind that bit about harder vs softer lube. I was dumb enough to try mixing candle wax and alox to use as a lube and whatever was in cheap candles was so stiff even with alox it was a mess. Whatever it is about beeswax is the magic number when added with alox.

Maven
06-09-2015, 06:29 PM
Tallbald, There's an excellent article by Jim Lewis [on that subject] in "The Fouling Shot," #235, May-June, 2015. It's titled "Bullet Lube: Some Random Thoughts" (pp. 235-23 - 235-24). It's worth reading!

44man
06-10-2015, 09:21 AM
I say "Thank the Lord for bees." Another thing that really helps a lube is lanolin.
I knew Felix and talked a lot with him although long distance. I wish I could have met him.
I knew of his health and he told me to say nothing and I respected that. It was a shock when he passed. The man knew lube and I will forever use it.
Now Glen knows lube too and he made the best BPCR lube I ever seen but he can't get the ingredients any more. It could have been a world burner in the sport.
The best thing you can do is to buy lube from Lar's. A great man that will not cheat you.
I have bought some of the worst lubes ever and found quick how much money I lost. I have a drawer full that will never go on a boolit.
I wish all of you would understand how important it is.

sundog
06-10-2015, 10:32 AM
Yup, Felix was quite a guy. I am proud to have known him and call him friend. He did a great service to the cast bullet community when he gave it Felix World Famous Lube. One of the best things about making your own lube is being able to experiment with it. When he and I made the 'Big Batch' years ago he adjusted the original formula by adding jojoba oil and micro paraffin. We made gallons of it in one single batch, and it was some good stuff - got shipped all over the country. I'm working on the last loaf of it (I got all the leakage, spillage, and over pour), and when that is used up I'm going to make some more. It's that good.

I noticed that in his article Glen mentions Sta-Lube/Beeswax. I used that stuff years ago (thought it up all by myself) in a Colt 1917 revolver that I had a problem with do to a well worn barrel. With that lube and a .454 sized Lee 255 gr RF, that old pistol's life was restored. In fact, what was left of the rifling cleaned up really nice. Good lube, but it stinks.

Glen gets a big 'attaboy' for the work he's done. Lots of exceptionally good documentation.

Lately I've been experimenting with Ben's Liquid Lube. Seems to be pretty good stuff. Never much cared for or got good results with Lee liquid alox, but mixed with the Johnson's liquid floor wax, it seems to do pretty well.

About running out of lube. A shooting buddy has a Rossi 45 Colt rifle (the long barrel). The Lee 45-255-RF with its two shallow grooves runs out of lube the last couple/three inches of that barrel, not really leading but a heavy gray wash. Same loads work just fine in pistol and carbine. So, it's not always the lube, other factors such as bullet design can affect performance. And that has everything to do with Tallbald's question about lube migration. Part of lube's job is to lay down a film for the next round, and when this does not happen performance suffers.

Well, that's my rambling thoughts for the moment...

9.3X62AL
06-10-2015, 03:44 PM
Another over-simplification here to cater to my less-than-scientific mindset......I have heard an analogy that likens the bullet to a free piston in an internal-combustion engine. The barrel wall takes on the role of the cylinder, the drive bands of the bullet function like piston rings, and the bullet lube acts as engine oil--both lubricating the bullet's/piston's passage and enhancing the compression seal of the piston rings/drive bands with the cylinder wall/barrel wall. Extending this analogy a bit further, the lube's place in both systems is CRUCIAL--close fit of all components assures more efficient performance and extends both reliability and duration of performance.

44man
06-11-2015, 09:03 AM
Thank you Sundog, my feelings too.
There is a point to compare to an engine but pressures are not the same and also metal to metal is not the same however fit has changed engines today. Used to wear an engine fast but they are fit so well today, most engines outlast the body, 300,000 miles or much more. Oils are like lube for boolits, so much better then ever.
I remember where I worked at UAL, they used Havolin oil and our tractors would wear out so fast they were always in the shop. I was given some once to put in my Chevy before a hunting trip and got half way there when clouds of smoke poured out the rear. Blew the engine. Oils have changed but we have only a few ways and ingredients to make boolit lube.
Testing has shown so much difference in accuracy I was amazed. Could it be? I would buy lubes and bought into the hype with each. Some work better in a slingshot pouch!
Alox was made to protect cars from rust and I think Zebart was Alox. I would spend extra to get Zebart and cars rusted FASTER because it came loose so salt was under it. Then my last Chevy truck got Rusty Jones on it and it never rusted in Ohio and when I sold it, it was still solid. The stuff was clear and and never came loose. I do not know who decided Alox was a boolit lube! It seems to have a very low flash point. Peanut, safflower and Jojoba oils are better. Whale oil worked and Jojoba replaces it but I still have a bottle of real whale oil. Fish oil was used in transmissions but they have gone to seed based oils and Lubegard Valve and assembly lube is good. 100% seed based oil. Makes a wonderful BP lube.
Once you work out a load, test lubes, you will see.