Mega lube groove theory

[JeffinNZ]

Team.

Playing Devil's Advocate here, as I tend to do.......

PART 1

I have heard it suggested that bullets that carry LOTS of lube aid in keeping fouling soft in BP shooting as the lube gets deposited in the bore and blends with the fouling. Thing is, given the near perfect gas seal generated by the bullet in the bore and the musing of Mr Fryxell regarding how lube atomises and produces a liquid pistion ring...............how does the additional lube get off the bullet into the barrel? The theory suggests more lube on bullet results in more lube in bore. I tend to think more lube on bullet results in more lube flung from said on exit from bore.

PART 2

Let's think about the internal surface area of a .45-70 barrel 30 inches long. Let's take the average diameter of the inside of the barrel as 0.454 (half way between bore of .450 and groove of .458)

= Pi x radius squared x barrel length
= 3.14159265 x 0.454/2 squared x 30
= 3.14159265 x 0.051529 x 30
= 4.8565

That's 4.8565 square inches of internal surface area. Draw a square 2.2 inches each side on a piece of paper and apply evenly to this square the amount of lube your .45-70 bullet carries. Did you cover the whole square? I think not.

SOOOOOOOOOOO reader. Do either of these theories stack????

[Boerrancher]

Jeff,

You make my brain hurt sometimes. I think I need a roll of duct tape to keep my head from exploding after trying to digest all of that.

Best Wishes from the Boer Ranch,

Joe

[Blammer]

I'll bet if you take the amount of lube on a boolit and put it on the paper and "melt it'' it will soak into all of the paper and thus lube it.

[Blammer]

pluse you're going to shoot more than one bullet right?

soget about 10 boolits worth of lube and put it on the paper and melt it.

na, wait, get about 50 boolits worth of lube.. :)

[JeffinNZ]

Jeff,

You make my brain hurt sometimes. I think I need a roll of duct tape to keep my head from exploding after trying to digest all of that.

Best Wishes from the Boer Ranch,

Joe

Sorry Joe. My mind wanders you know. [smilie=1::-D

[Bigjohn]

Jeff; I think you have too much time to think (up things like this).

I am not an eggspurt :coffee: in the science of shootin' things but I know your in for mega problems if you don't lube. As I found out yesterday with the .310". The lube had run (melted) off the old rounds I shot the match with. Some of the leading I pushed out with the cleaning patch were a centremetre square and 3/4 of a milimetre thick.

I am lead to believe that when we fire the cartridge the base of the boolit starts to move before the nose (kind of like what happens when someone gives you a good solid boot up the backside :twisted:) ((I'm not hinting we should come over and give you one [smilie=1:)).

Your maths looks alright on this one, keep on thinkin', Jeff.

As the length of the boolit shortens so does the capacity of the lube grooves and this squeezes the lube outwards and onto the bore.

Beyond that I'm lost,
Best wishes;
John

[longbow]

I can't say exactly what happens or even how but... in my past experience with a Marlin 1895 .45-70 microgroove barrel I used to shoot a Lyman 385 gr. round nose lubed with - wait for it - Valvoline wheel bearing grease over a full case of BP. I know many say petroleum based lubes are no good with BP but this worked for me.

At the end of a shooting session I would push several patches through the bore and they would come out very mucky, covered in black soft stinky fouling. Afterwards out would come the Hoppe's and gun oil to clean and preserve the gun.

Now I agree that the boolit seals the barrel and that there really shouldn't be much lube left after a sealed boolit zips down the barrel but that was my experience. It seems more lube was left than there should be. Possibly the boolit "floats" over the lube by compressing the lead a little and leaving a very small clearance for the lube coating.

I have read that too much lube on a boolit can result in poor accuracy due to the boolit "floating" and have experienced what I think is just that with my .303 and Lyman 314299's with extra lube on the nose (dip lubed). Accuracy returned when the lube on the nose was removed.

If there was no coating of lube in the bore after each bullet, how would a lube star form? I think each boolit pushes some lube out the muzzle and leaves its own deposit for the next boolit to push out. How thick is that deposit...?

Now my brain hurts.

Longbow

[S.R.Custom]

Liquid piston ring? I don't buy that one at all. 8-)

[oneokie]

Team.

Playing Devil's Advocate here, as I tend to do.......

PART 1

I have heard it suggested that bullets that carry LOTS of lube aid in keeping fouling soft in BP shooting as the lube gets deposited in the bore and blends with the fouling. Thing is, given the near perfect gas seal generated by the bullet in the bore and the musing of Mr Fryxell regarding how lube atomises and produces a liquid pistion ring...............how does the additional lube get off the bullet into the barrel? The theory suggests more lube on bullet results in more lube in bore. I tend to think more lube on bullet results in more lube flung from said on exit from bore.

PART 2

Let's think about the internal surface area of a .45-70 barrel 30 inches long. Let's take the average diameter of the inside of the barrel as 0.454 (half way between bore of .450 and groove of .458)

= Pi x radius squared x barrel length
Uhh, here in Oklahoma, that is the formula for calculating the Volume of a cylinder.
= 3.14159265 x 0.454/2 squared x 30
= 3.14159265 x 0.051529 x 30
= 4.8565

That's 4.8565 square inches of internal surface area. Should read 4.8565 in³ of volume.


The formula for surface area of a cylinder is----Pi x Diameter x length.

No, I am not going to do the math, my head hurts enough as it is.

[dwtim]

I have contemplated your post, and offer the following:

[Harry O]

One thing not mentioned so far is that the "big lube" bullets are longer than "standard lube" bullets for a given weight. If your twist is marginal, they won't work. I bought a sample of 500gr 45-70 Big Lube bullets. They were quite a bit longer than standard 500gr 45-70 bullets. The twist was not adequate in my gun and every one of the big lube bullets keyholed in the target.

I shot a 405gr standard lube bullet and it was adequate, but the bore had to be cleaned reqularly to shoot accurately. I am currently shooting a 300gr standard lube bullet with good accuracy, but I am looking for a 350gr bullet to try.

[leftiye]

No doubt the lube coats the barrel - Assuming you keep the first few rounds from leading (pre lube the barrel?). A lube of the "proper" sort does adhere to the metal of the barrel as (while) the boolit passes over it = definition of lubrication. Worse case scenario, the boolit is deformed by hard lube deposits (but that's another scenario).

Point being that lube forms a layer between the boolit and the bore. Glen F. on LASC listed I believe three ways the lube gets from the boolit to the bore. As was said this doesn't necessatily happen with one or two bullets, but it does come about. Or else you will get leading.

[94Doug]

Tim,

Thats Beautiful. I think too long for a standard Lee 6 cavity though. No group buy.

Doug

[JeffinNZ]

I have contemplated your post, and offer the following:

If you made this bullet two piece with a thread in the middle you could just get a stick of lube, insert a piece of the bullet at each end and screw them together!!!!


The formula for surface area of a cylinder is----Pi x Diameter x length.


Quite correct. I worked bore volume.

Surface area is 42.79 square inches. Worse than we thought.

I don't believe lube deposit is cummlative. To a point it will be but it the lube continued to build the bore would close over.

[oneokie]

An idle mind is a dangerous thing. [smilie=1:

From what I have seen posted here on boolit designs, loob grooves have their capacity stated in cc's/ml's.

For those who like to crunch numbers, I suggest this; determine the total volume capacity of the loob groove/s in cc's/ml's,

then do this; calculate the surface area of the bore in question,

then crunch the numbers to determine what the thickness of lube would be in microns for the above determined surface area.

My cowboy math says that for the example Jeff posted, it would take .004274 microns³ for a 1 micron thick film of lube in that instance. Converting this to cc's/ml's is beyond my skill set.

Logic tells me that it does not take much lube thickness to achieve the desired results for avoiding leading of the bore.

[JeffinNZ]

Indeed.

You can see from that why I don't believe the lube is going to assist in keeping BP fouling soft though. When you consider how much fouling is left in the barrel compared to the VERY thin layer of lube the poor old lube doesn't stand a chance. UNLESS the critical factor with BP fouling is NOT keeping the fouling soft but stopping it adhering too tenaciously to the steel.

Hands up all those with sore heads! [smilie=1::drinks:

[oneokie]

UNLESS the critical factor with BP fouling is NOT keeping the fouling soft but stopping it adhering too tenaciously to the steel.

Hands up all those with sore heads! [smilie=1::drinks:

That I would think is a very good answer.

[dwtim]

I hesitate to take a serious whack at the question, because I see it pertains specifically to BP shooting--but, does it have to be evenly distributed? I've done much observation with test loads in my guns; I used to bring a little MagLight to inspect the bore every few shots. What I noticed about loads that progressively fouled is that even though the extent of the fouling was different, it followed the same pattern:

The first deposits appear just ahead of the case mouth

Next a ring forms around the forcing cone (revolvers)

Then another ring forms where the rifling begins

The fouling progresses a couple millimeters; the grooves ahead of the lands

Thin streaks of lead appear in the corners of the grooves, and progress to the muzzle; usually in an uneven fashion

Heavy, high-relief fouling progresses up the bore (I usually stop shooting at about 1/3 coverage)


Maybe one or two of my handguns show an even distribution of fouling. Honestly, how many absolutely perfect guns do we own? A drop or tilt barrel auto loader will wear faster on the bottom half of the barrel, for example. What about a revolver where the chamber alignment isn't perfect? Or a rifle with an off-center chamber? Barrels have tool marks all over them, and millions of microscopic imperfections, no matter how much lapping is done.

Perhaps it isn't so much that there is a 1 micron coating of bullet lube, but the lube fills the imperfections that exist. There is no doubt that lubes have less surface hardness than even pure lead, and compress easier. I'd be willing to bet that wax--and say, Alox--can fit in tinier spaces than the crystals that form in common bullet alloys--and will probably squeeze into larger nooks more readily. (Up to a point, of course, since the lack of lube hardness means it can easily be blown out of the way if it spans a large gap.)

So in this respect, it's important that the "lube" reservoir is sufficient so that pressure is maintained while the bullet is compressed, (because the metal will only compress so far for a given pressure); so that imperfections are filled, and gas leakage is kept to a minimum. It's all a balancing act, regardless. One little thing like the wrong alloy, size or some defect in gun dimensions will ruin it.

I likewise have wondered about the effects of lube on lead removal. I recently switched to a soft commercial lube (actually I mixed two by accident), and I swear that even a badly fouling load only takes a few of brush passes to clean up. I've been considering using this lube as a barrel treatment. I've tried Kroil-ing the bore (but patching before shooting) and have noticed easier removal of fouling afterward. I swear that over-scrubbing a bore, or using strong cleaning chemicals to take the metal down to the white results in lesser accuracy and more difficult fouling, until the bore becomes seasoned once again.

[357maximum]

I swear that over-scrubbing a bore, or using strong cleaning chemicals to take the metal down to the white results in lesser accuracy and more difficult fouling, until the bore becomes seasoned once again.


THEN THERE ARE THOSE WHO NEVER CLEAN A BORE IN A SMOKELESS CAST BOOLIT SHOOTER.....NOT UNTIL AND ONLY IF THE IRON SAYS THAT IT NEEDS IT.[smilie=1:

[spurrit]

Well, when I shoot several hundred rounds in a day, I occassionally notice a considerable amount of flame from a load that feels, sounds, and hits just like the others. I attribute this to an excess of lube building up, them atomising, then catching fire.

This leads me to the conclusion that, as my barrel heats up, the bore expands enough to prevent a "perfect seal", thereby allowing a vacuum effect to swirl around the atomised particles and ignite them.

Or, alternately, I could be just completely full of @$#%. I'd believe either, really.

Yup, you read that last part right. Someone on the internet believes they could be wrong. :roll: I know I just made someone's day!