Tumble lube and grooves?

[singleshot]

I've tumble lubed all different kinds of cast boolits. Lately, as I tumble lube some boolits, I said to myself "Self, what's the purpose of the grooves? Why not design some type of 'paper patched' boolit for this since more lube will actually adhere to the boolit?" Sometimes I talk to myself while casting....
Anyway, can anybody help me with this dilemma? If you tumble lube, why have lube grooves?

[462]

Well, this is obviously a case one of not getting the right answer, or possibly no answer, when talking to oneself. Often, I've asked myself if there were others similarily afflicted. It's taken a long time to get the affirmation. Thank you, Singleshot.

I don't tumble lube, so can be of absolutely no help.

[singleshot]

Thanks for the response anyway 462. Glad to know there's more out there! Does your response voice use a different voice?

[FLDad]

I do tumble lube some of my boolits, and it took me a long time to realize that I was applying way too much. Switching to 45-45-10 helped some. So I guess maybe finding new ways to add more lube might be moving in the wrong direction. Just enough to prevent leading close to the muzzle seems like the right amount to me, so maybe that should be the litmus test. Those with more experience may take another view.

[Cowboy T]

Why the lube grooves for tumble lubing? I'd imagine it's to reduce the bearing surface and thus friction, kind of like how Barnes does with their new TSX bullets. And it's true that you don't need a lot of tumble lube. A little goes a pretty long way.

[singleshot]

I do tumble lube some of my boolits, and it took me a long time to realize that I was applying way too much. Switching to 45-45-10 helped some. So I guess maybe finding new ways to add more lube might be moving in the wrong direction. Just enough to prevent leading close to the muzzle seems like the right amount to me, so maybe that should be the litmus test. Those with more experience may take another view.

Yes, I definitely agree with you. I didn't explain my thoughts regarding this. I guess that happens when you converse with yourself too much.

I haven't had any leading problems with tumble lubing. I was thinking more along the lines of less complicated designs, higher BC boolits and increased bullet mass for a given length/design.

In fact, I've had such good results with tumble lubing, I was wondering if there's a better way or should I just leave well enough alone?

[singleshot]

Why the lube grooves for tumble lubing? I'd imagine it's to reduce the bearing surface and thus friction, kind of like how Barnes does with their new TSX bullets. And it's true that you don't need a lot of tumble lube. A little goes a pretty long way.

Good thoughts, Cowboy T! That may very well be the final answer. I understand the importance for a Barnes bullet to look to decrease bearing surface due to the relatively hard bullet material, but I wonder how important that is for Pb tossers?

[HARRYMPOPE]

I have used lee alox on smooth a .310 diameter 135g 30-06 load with good luck at 1200 fps.It was a RN core mold of some kind, just tried it to see if it worked.My guess is it would work with a std bullet shape smooth,but without grooves of some sort most would be scraped off the body during seating.But i have shot many bullets without lube at all at 1200-1600 fps and accuracy is better than most would think,sometimes for up to 100 or better shots.You can shoot under 2MOA in a good 30 or 35 cal this way with a GC bullet sans lube.

Somebody should have Erik Ohlen machine the lube grooves out of one cavity of a mold and do a serious comparison.

HMP

[Gohon]

most would be scraped off the body during seating.

Exactly...........when you seat a bullet that's tumble lubed, the lube is scraped off the sides and rolled into the grooves. So those grooves still serve a purpose even in tumble lubing.

[onondaga]

I tumble lube everything with 45:45:10 and read on this board a member sizing off the TL grooves. That , to me would be the time to select a different bullet mold. I think that even sized almost flat that if there is still a little groove left that helps. The increase in surface area with the shallow grooves helps hold a little extra lube. Completely flat like a paper patch bullet is something I haven't experimented with. I'm not saying it wouldn't work. I always judge my lube by the muzzle and if it isn't there in 5-10 shots and showing a star something is wrong. I haven't had that problem since I began using tumble lube. I like the stuff, I like the method. If a smooth paper patch type bullet carried the lube to the muzzle, I'd keep using it with the bullet.

The plain base bullets for rifle I tumble twice. Gas checked/sized bullets I tumble once before check/sizing and twice after. 100% satisfaction. I do think undersized bullets will lead to lube failure with tumble lube as the lube will be blown past the bullet by gas jetting. I avoid that by slugging bores and good bullet fit.

Maybe my alloys help. I don't know for sure. But I only use 2 alloys and both are with Wheelweight and Linotype mixes and BHN for them is 14 and 20 as cast. The harder alloy with gas checks and tumble lube I have taken to 2700 fps in .223 Rem. without leading. Accuracy was below average at 2 MOA at that speed but the bore stayed clean. 2550 fps peaked accuracy at 1 MOA with that bullet in a single shot heavy barrel NEF Ultra Rifle with 1:12 twist.

My tumble lube doesn't get shaved off seating bullets due to my using good practice of "M" expander dies or or size correct expander bells in sizing dies and then using an universal case mouth flair die. I also optimize avoiding that problem by using the Frankford Arsenal case mouth prep kit with caliber specific brushes and powdered mica to clean polish and dry lube inside case mouths.


Gary

[462]

"Does your response voice use a different voice?"

Different voice? It's an untranslatable language.

[HARRYMPOPE]

i often thin lee Alox with mineral spirits and the thin single coat works well up to 2100 in .30 caliber with linotype/ww mix.A clear carnauba wax product used for wood string instrument care was sent to me by a prominent benchrest gunsmith to try and it worked up to 2700 and MOA in 22 caliber.

HMP

[blackthorn]

I tried asking myself questions and didn't get an answer so I thought why not ask an expert? SO--I closed my eyes and concentrated real hard and asked my question of Elmer! I kept my eyes closed and waited---and Elmer said----Go read the stickies and then use the search function on the Cast Boolit Board!!! Have a great day!

[singleshot]

I tried asking myself questions and didn't get an answer so I thought why not ask an expert? SO--I closed my eyes and concentrated real hard and asked my question of Elmer! I kept my eyes closed and waited---and Elmer said----Go read the stickies and then use the search function on the Cast Boolit Board!!! Have a great day!

I'm really glad Elmer is able to keep up with technology, but a little perplexed (but not that surprised) that he didn't throw me a bone.

Any search on this subject results in hundred if not thousands of irrelevant threads and comments to pour through. I think I've done due diligence:

After months of research on the subject, and without experimentation of my own, here's what I've surmised, echoing quotes of other members on this forum:

"A decade or so ago we had a long thread on the how's and why's of lube grooves and their function. In the end there were a couple of good theories, but few facts. I'm afraid much of lube groove design in the "beauty in the eye of the beholder" as anything else. "
- bret4207

"If you're using an inferior lube or trying to keep fouling soft a big honkin load of lube on a bullet might be best. Use a decent lube with smokeless powder and you can get along with just a bit. A fine thread screw is stronger than a coarse thread screw because the minor diameter is larger. Why would you want to weaken a bullet by cutting a deep wide groove?"
- Pat Iffland

At the end of the day, there may not be a "researched and tested" answer, and that's ok. But before I start plunking down experimentation $$$, I want to know if there's any experience or at least what the experts think currently.

Keep in mind, some of the threads on this subject in this and other forums are years if not decades old.

[SkookumJeff]

Good discussion, although I'm confused, I'm hearing lots of voices but not sure as to exactly how many 'people' are talking here?

Begs the question, is there such a thing as 'too much lube'? I thought I read somewhere that this could happen?

[singleshot]

I'll attempt to draft a response that concisely concludes my current theories. I'm becoming more convinced that boolit lube's primary function is not lubrication. Lead is a very soft substance compared to steel. Lead is a decent lubricant itself. I've shot completely 'unlubed' lead in low pressure situations with no leading evident in the barrel. I've shot copiously lubed lead at higher pressures with leading. Without compiling a book here and now, here are my main theories to date:

1. Pressure is the main obstacle with lead boolits, not heat or lubrication
2. Boolit lube's primary function is sealing gaps created by pressure as it creates fissures in the bullet
3. The consistency of the lube should match the pressure in that it must be viscous enough at a given pressure to flow, but resistant enough to seal the fissures that form

Some other factors to consider:
Jacketed bullets have no lube.
Copper is a very poor lube compared to lead.
Gas checks help curb leading even though gas checks do nothing to lubricate.

Trying to keep this short, so fire away on these theories and factors.

[singleshot]

Ok, just found this on a totally unrelated topic, but I think it adds to the discussion:

"Recluse, I think among boolit lube experimenters there are two schools of thought. One is what most beginners think and the other is what they think after they discover through experimentation that what they thought was wrong.

The first thought is that lube works by keeping lead from sticking to the bore by forming a non-stick barrier, much like Teflon on a skillet. Veral and Dan both seem to still think this, I don't know why. Then, when the magic non-stick stuff fails and lead DOES stick to the bore, we are left wondering why. Then, maybe, eventually, we learn that boolit lube does much more than lubricate, and that lead deposits in a gun barrel get there by means other than abrasion or lack of lubrication. Lube prevents leading by helping to prevent gas-cutting and the resulting particles of lead being blown ahead of the boolit and ironed on the bore as the boolit passes over them. This is easily proven if you take the time to induce gas-cutting, recover boolits, and observe bore condition. Then, once we get boolit fit, alloy and hardness, lube type and viscosity, barrel condition (restrictions, roughness, etc.), and the correct powder, primer, case tension, crimp etc. required for a gentle LAUNCH ironed out and finally cure LEADING, then we find out that our real challenge isn't preventing leading at all, it is ACCURACY. So we hang on to our original theory, we must find the best, slipperiest, be-all end-all whizbang slickum to reduce friction and give is our beloved accuracy, right? But we try it and it doesn't work! We buy every infomercial miracle engine treatment we see, try aircraft lubes, tool and die lubes, EP grease, synthetic formulations and additives of every kind thinking it must be an improvement. Then, once in a while, we load up some of those old boolits we lubed with Lyman Alox back before we knew everything about lube, go to the range, and find it shoots better than anything we were able to concoct. *sigh*. What makes that stuff work? What are it's limits? Why does it have limits and what factors affect that? Again, we find that accuracy is dependent on as many, and often the same, factors as lead fouling, and we start our lube quest anew. Now, we find that lubricity and viscocity are probably the most important factors to accurate function. AMOUNT of lube is also paramount to consistency in rifles, as just the right type and amount is required for consistent, shot-to-shot bore condition without accumulation and the resulting "purge fliers" many of us have experienced. Change one thing slightly, and often lube has to me altered to match the condition. Boolit lube is truly a balancing act, and can be a sort of razor's edge between slickness, stiffness, temperature range, and amount. Much more than a non--stick layer.

Interestingly, and someone here has proven it, most wax/oil based boolit lubes make excellent soldering fluxes, so they certainly don't work by prevention of lead adhesion directly.

Then, a monkey wrench in the lead-free = best accuracy theory. Has the following ever happened to you?: "Wow! I just shot the best group ever with this (insert your experience) gun, but to my horror found it leaded the bore! I went ahead and and continued shooting, getting many more groups just as good, the leading didn't get worse or better, and the gun still shoots like a laser!. Later I cleaned it and it took three boxes of shells to get it shooting straight again, but this contradics everything I thought I new about accuracy, lube, and leading!" So now we start to accept the possiblity that keeping lead fouling to a minimum might not be a requirement to THE most accurate load possible.

This is the short version of the experiences that have brought me to what little understanding that I do have of lube and its function. I learn something every time I go to the range, and add it to my list of observations to be mulled over on rainy days, trying to distill the most important attributes of lube down to just a few things, and dreaming of the perfect subtances that would fill those attributes at any velocity, pressure or temperature. So far, I've tried just about ever commercial concoction out there, and the only thing that meets ALL of my needs is Felix lube, although slight tweaks are necessary to cover the gamut. At least I understand it well enough to know what tweak to make and when.

Now, let's look at bore coatings. I tried using a coat of Bullplate on bone-dry, freshly cleaned and stripped bores, letting it soak overnight and patching out before shooting to give the bore a fighting chance on not leading, what I found is that if the load is good, it does nothing except fling the fouling shot even higher. With undersized boolits nothing I have ever tried for bore coatings or lube will prevent leading from the resulting gas cutting. This leads me to believe that bore coatings won't prevent leading only by the action my making it non-stick, but that there are other factors at work. I aim to discover what they are.

Gear"

[stubshaft]

You are taking one component and asking how or why it will cure all ills. It is like baking a cake and asking why should we add vanilla extract.

There is no easy asnwer because ALL components interact with each other. Yes you can have great accuracy with a boolit that leads. You can also have crappy accuracy with a boolit that leaves the bore shiney and has a SD of 1.

The only TL boolits I own are RD's. I have tumble lubed conventional boolits and have gotten results on either side of the spectrum as well as lubing and sizing TL boolits.

I personally subscribe to Veral's theories because they work for me, and I can understand the interaction of components with them. I have used his components and considered him a friend for over 28 years.

But theories being what they are, every one has one. They develop them by experimenting to see what works in their gun, with their alloy, using their powder and preferred primers.

There is no one answer to what creates the best accuracy for you.

[462]

Singleshot,
I don't have the answer, but here's an article to ponder: http://www.lasc.us/FryxellLubeCastBullets.htm

Gear's comments -- thank you, sir -- will require a second or third reading.

[singleshot]

Singleshot,
I don't have the answer, but here's an article to ponder: http://www.lasc.us/FryxellLubeCastBullets.htm

Gear's comments -- thank you, sir -- will require a second or third reading.

462, thank you for your time and research. I've read fryxell's article on cast bullets along with just about everything else he's written. In fact, this is the precise article that caused me to start experimenting and pondering even though I blindly stumbled into something that worked fine when I first started casting about 4 years ago.

That being said, I think this is an outstanding article and is worth re-reading and bringing up in this thread!