What does boolit lube really do?

[RandyGA]

http://www.lasc.us/FryxellLubeCastBullets.htm

After reading this and thinking a bit, which may be the wrong thing to do..LOL, as long as you use lube, no matter what kind, you should be good to go as long as you are sizing properly. Besides, if you buy jacketed bullets they are .308 for a 30 cal, why worry if your cast is .308 or .314?

[runfiverun]

uhmmm.
lube does several things, one is to leave some lube behind.
another is to act as a seal to keep gas from passing through where the boolits meet the lands.
it also has to have enough lubricity to make it all the way down the bbl.
if your bbl is 308 you can get away with using 308, your nose needs to fit,and the shape of your boolit needs to mimic the leade and throat as closely as possible.
the whole point is to seal the bbl as well as possible.

[mdi]

A lot of opinions on this question, I'm sure! I don't have a definative answer, but I have my own ideas of how lube works so I'll defer to an expert: http://www.lasc.us/FryxellLubeCastBullets.htm

[870TC]

Lube, among other things, gives us something to ponder late at night and something to talk about the next day.

[runfiverun]

much of what glen writes he takes from lyman and lee.
it's a good high school education on casting stuff.
not knocking him any, he just does the generic and covers the basics.

[ammohead]

Ideally lube keeps the lead from touching the steel. Ideally.

Bullet fit seals the gases as best it can. But if all you had was a tight lead to steel fit things would not come out to well. So we try for as tight a fit as possible with lube coming between the two as best it can. It is amazing that it works as good as it does.

ammohead

[geargnasher]

The trick to boolit lube is balancing lubricity with viscosity.

Why it matters is a subject of debate because nobody really, really can prove with test instruments what goes on inside a gunbarrel with regard to lube. We can only examine the evidence and deduce what happens, and that's where individual results lead to individual, and differing, opinions of the what/how/why of lube.

We assume that the lube lubricates, right? But what does that mean? To me, it means just what Ammohead said, it creates a dynamic film like the lubricant layer on your eyes that keeps the boolit from actually touching the bore. Same concept as plain bearings used in automobile engines, the basic function of any lubricant.

But it takes more than a squirt of 30-weight on a boolit nose to keep accuracy good and leading out, right? Why? I think that's where viscocity comes in. Lube can't do it's main job if it isn't where it's supposed to be exactly when it's needed, right? The lubricant needs a high-viscocity carrier to keep it from blowing out through the tiny gaps and leak areas around a boolit as it travels down the bore. This viscocity must be balanced to the pressures involved, that's why I think my experience with low pressure/hard lube has generally been bad, and why lousy, soft lubes with poor lubricant ingredients don't work at 40KCUP and 2500 fps. This is Glen's "ballistic stop-leak" theory, and I think it holds true for the most part, but how much or little depends on how good your barrel/boolit fit is.

How liquid Alox works still baffles me.

Gear

[Von Gruff]

With regard to some of the above reasonings that the lube creates a microscopic layer between the alloy and the steel I ask this. How does this work with a long bore riding design. I run a 7mm boolit that is an inch and 3/32 long but 7/8 to the front of the bore riding portion so to all intents and purposes call it a 7/8 alloy to steel contact with a single lube groove, but the front of the lube groove is only 5/16 from the base and while there (may be) some hydrolicing of the lube forward it still leaves 9/16 of the alloy un lubed for its travel down the barrel and yet at 2415fps I get no leading, albeit with a lino alloy.

Von Gruff.

[runfiverun]

gears first sentence covers a lot of the how. actually most of it.
lube is as much a repair mechanism as a lube. it probably don't leave a film along the boolit,as much as it seals the corners of the lands and grooves.
you cant just find the slickest stuff out there and put it in a carrier.
it has to work like e.p grease does.
i am a fan of lubes about as consistent as playdough.
for years i got along fine with the commercial plastic lubes in my handguns and rifles. [at times i modified them slightly]
they worked very well for the loads i was using.
but i wanted to do more [hunt, high vel] with lead boolits and the lube needed to keep up.
once you go through the threshold of velocity in a rifle [or even a super magnum] things need to be balanced, and each step becomes harder.
lube becomes more and more important as the pressure and gas volumn increases.
you are already using a gas check,made sure the nose fits,and you've filled the throat properly.
made the boolit harder to keep it from skidding across the rifling, and started it out as gently as possible.
the only two things left are to protect the base of the boolit more, and to make sure you are not leaking gas through everything all the way down the bbl.
lube is the one thing that is flexible and fluid [not liquid] in the whole equasion.
ingredients their interaction and viscosity of the whole becomes more important as more demand is placed on them.
if you look at felix lube he uses castor oil as the actual lube. mineral oil is used to help bind the castor oil and as a modifier [thats why the high heat is required], and sodium stearate is the actual binder to keep it in the beeswax.
it's also a lubricant.
if lanolin is used it helps keep the b-wax flexible and adds tackyness to the whole thing.
now if you don't use the mineral oil the whole system won't work.
no sodium stearate?
nope don't work again.
the castor mineral mix is likely to bleed out of the b-wax without the binding agent.

[fredj338]

http://www.lasc.us/FryxellLubeCastBullets.htm

After reading this and thinking a bit, which may be the wrong thing to do..LOL, as long as you use lube, no matter what kind, you should be good to go as long as you are sizing properly. Besides, if you buy jacketed bullets they are .308 for a 30 cal, why worry if your cast is .308 or .314?
That's not really how I read it, but everyone comprehends things diff. Pressures seem to be what decides which lubes work better than others. Bullet fit is always king, but a lube that fits the pressures you are working in helps a great deal. IF it were only about lube, then one could use Crisco for everything & that just doesn't work out.

[geargnasher]

My explanation of the bore-rider is twofold: One, I tumble lube all my bore-riders in 45/45/10 before sizing and lubing with Felix lube, so they aren't unlubricated. Second, the bore-riding section isn't exposed to gas pressure, only friction of metal-to-metal contact with the bore lands, and it's unlikely that even with the first shot that there won't be some trace of an oil film on the barrel steel. If you cleaned your barrel with boiling soapy water and shot a dry-nosed bore-rider through it you might get some lead rubbed off the lands in the cuts left by the bore drill, but otherwise not likely with a normal "seasoned" bore. This is where I theorize that the lube residue from previous shots does a little bit of "prelubing" the bore, albeit not much. The behaviour of the bore-rider is also what makes me believe that the lube also acts as a stop-leak as much as it does a lube. Most of our leading seems to take place due to combustion leaks cutting channels clear past the boolit and depositing the powdered debris ahead of the boolit to be ironed on as it passes. Very little leading is caused by friction alone, and the metals have to be dry for it to adhere. Once the leading process starts, more lead sticks to it and it can create a snowball effect sometimes. Other times the bore leads to a certain point and then stabilizes without affecting accuracy.

I base my theory of boolit lube "lubing" based on velocity and POI results from different lubes or adjustments of proportions within a single recipe, different temperatures, and different amounts used. I base my stop-leak theory on recovered, gas-cut boolits and the results of that gas-cutting on the bore, and also from the way lead deposits form in the bore downstream of thread chokes, roll-lettering crush, front sight crush, etc. Sometimes changing to a much higher-viscocity lube can band-aid a barrel restriction to the point that it stops the leading. Use of a softer or more malleable alloy can do the same in some instances, reinforcing my theory that obturation prevents leading almost all by itself. I haven't been able to shoot an unlubed boolit with a positive, leak-stopping filler like BPI original without leading the bore to buggary, so I maintain that a small amount of high film-strength lubricant is necessary to prevent leading completely. I know that weakens the bore-riding argument, but I'll bet bore-riders would lead badly without some lube in the system somewhere.

So you can achieve a leak-free seal between the bore and barrel and get leading with no lubricant, and you can stop some mild leaks with high-viscocity lube, and you can tweak the lube to work best with the velocity and pressure you need, so I think a lube serves to lube, seal, and prepare the bore for the next shot by leaving a consistent trace behind. This last part is often overlooked by people until they get into higher-velocity pursuits with rifles where the "purge flyer" effect happens every few shots. After you start trying to come up with ways to solve this it pretty soon becomes apparent that amount of lube used is just as important as composition and viscocity. You need just enough to escort the boolit out of the barrel and then jettison completly as soon as possible with as little accumulation left in the bore as possible to make shot-to-shot consistency.

Gear

[runfiverun]

:drinks:
hopefully all this explained lube and as much how it works [about as well as it can be explained]
and the reasons for using certain concoctions of lube.
easiest, general, and specialized.
i have done similar to gear on a bore rider, but used a home made b.a.c. and anhydrous lanolin-bees wax mix on the nose.
most other bore riders i run the nose clean and let the lube groove do it's job.
and generally don't use them unless the rifle absolutely calls for it.

[1hole]

"After reading this and thinking a bit, which may be the wrong thing to do..LOL, as long as you use lube, no matter what kind, you should be good to go as long as you are sizing properly."

Keep thinking, you ain't there yet.

[Blammer]

boolit lube really just gives us another thing to "tinker'' with. :D

[warf73]

boolit lube really just gives us another thing to "tinker'' with. :D

+1 on what Blammer said.

[Eutectic]

Maybe of most importance is a blast/heat shield.

I spent a good portion of my working career as a lubrication specialist. While I may know EP (extreme pressure) lubricants, Timken OK load numbers and other tools for proper lubrication of heavily loaded equipment; I think bullet lubricant marches to the beat of another drum....

I say this because some of the best EP lubricants don't necessarily make good bullet lubricant... Maybe OK, not the best.. "Magic" stuff like STP is included in the no help column!

Maybe I learned something many, many, years ago while still in high school... I had a machine shop class. In those days about all we used were high speed tool bits we ground ourself. We had a squirt can and squirted 'cutting oil' on a heavy cut to protect our tool from heat. Well, our container was out of cutting oil... so I filled my squirter with machine oil..."Oil is oil, I mumbled to myself."
Imagine my surprise when the squirted machine oil literally ran away from the hot cutting area around the tool bit!!!!

Years later I learned a lot more on 'cutting fluids' (not cutting lubrication, mind you!) I learned certain additives made the'oil' stay in the heat zone. (Sulfur and others) Now I date myself..... Steam cylinder oils for locomotives and reciprocating steam pumps used to have animal fat/tallow added so the hot steam wouldn't cut away the oil film away thus insuring fast wear! Imagine that.... tallow!!!!!!!!!!!! Where have we heard that used before?

I think the various Alox types are probably not high up on the lubrication scale of things but they fight the heat and stay put...

"Maybe of most importance is a blast/heat shield."