Random Lube & Fouling Ruminations

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DanTDesigns
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Random Lube & Fouling Ruminations

Post by DanTDesigns »

Random Lube & Fouling Ruminations: Excerpts for a long email sent to a friend.

I agree that bore finish will dictate which lube formulation as well as fouling control techniques work best. The rougher the bore, the more lube required. Also, the longer the barrel the more lube that is required. Chromoly barrels require more lube than stainless steel barrels. My take is that our BP lubes have three functions. First, they coat the bore so BP fouling doesn't stick. Second, the lube reduces the coefficient of friction between bullet and bore and thereby reduce the risk of leading. Third, if blow-tubing, the lube must allow for the fouling/lube mix to hydrate well past atmospheric conditions that just BP fouling will not hydrate in. BP fouling loses its ability to be deliquescent at around 30% relative humidity with temps over 90 F. When I first started shooting BPCR matches, when it was hot and dry, almost everybody's scores tanked due to fouling-out, because most were blow-tubing. It wasn't until the middle of the last decade that shooters transitioned to wiping when it was too hot and dry for their lubes to work. That was the motivation for developing the version of White Lightening BPCR Lube that Doc Lay and I use.

Lapping a barrel, especially a chromo barrel, can substantially reduce the amount of BP fouling that remains in the bore after a round is fired. Also, a highly efficient lube will reduce the amount of fouling remaining in the bore. I did an experiment about 10 years ago where a chromo-barreled, 38-70 rifle was shot and carefully wiped 3 times. Pictures were taken of the patches for 10 rounds. The barrel was then removed from the action and lapped to 400 grit (180; 240; 320; 400) using non-imbedding Clover compound. The next day the same test was performed. The first patch, post-lapping, had about the same amount of fouling as the second patch from the day before. The second patch, post-lapping, was almost clean. My take is that the rougher the bore, the more the BP fouling sticks to the surface roughness. The bottom line, for me, is that stainless steel barrels are superior with regards to reducing fouling issues, when shooting BP and cast bullets. My guess is that it's the same when using smokeless and cast bullets. Also, SS barrels also do not get as hot as chromo barrels, all other things being the samel.

In my mind, a lube that eliminates fouling and improves MV variation is best. The load just needs to be tuned to the barrel harmonics to tighten-up groups.

From all the work I've done with PP rifles, a clean, dry bore produces the best accuracy when shooting PP bullets. That has held for both chromo and SS barrels. Knurled bullets have been tried by a number of top marksmen and found wanting. Much testing was done during the last decade to determine optimum lube-groove design. SS barrels allow for fewer and smaller drag-inducing lube-grooves. For rough, chromo barrels, more NAPA oil, 20%, in the wiping solution has been shown to reduce leading.

In my mind an effective lube prevents fouling-related accuracy loss and reduces MV variation. Of course, to see those effects one's ammo must be match-grade. Poor quality ammo is the bane of serious testing, when it is used to explore various fouling control, component and reloading effects.

How much lube is really necessary? That depends on lube quality (efficiency,) barrel length, powder type, powder charge, bullet weight, SS vs chromo and smoothness of the bore. Just to elucidate the bullet weight, the heavier the bullet for a given load, the less fouling will be in the bore due to improved combustion. The improved combustion results from higher temp and pressure caused by the increased moment of inertia of a heavier bullet.
All the best...DanT..."The nation which indulges towards another a habitual hatred or a habitual fondness is in some degree a slave.” - George Washington’s 1796 Farewell Address
Orville
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Re: Random Lube & Fouling Ruminations

Post by Orville »

Dan
You say you get the best accuracy with pp bullets with a clean dry bore, is that when useing plain water to clean with and drying the bore, or your soluble oil water mix and then a dry patch? In my experience there needs to be some lube in the bore to get the most consistent results it dosn't take much, your oil water mix works or my lube wad after I wipe with a cleaning solution. The ODG were told to make sure they oil there bores the same every shot.
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DanTDesigns
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Re: Random Lube & Fouling Ruminations

Post by DanTDesigns »

Orville wrote:Dan
You say you get the best accuracy with pp bullets with a clean dry bore, is that when useing plain water to clean with and drying the bore, or your soluble oil water mix and then a dry patch? In my experience there needs to be some lube in the bore to get the most consistent results it dosn't take much, your oil water mix works or my lube wad after I wipe with a cleaning solution. The ODG were told to make sure they oil there bores the same every shot.
Orville,

I guess I should have added more detail to my observation that best accuracy has been had with a "clean, dry bore." The bore is cleaned of all BP fouling and dried with a 3", dry patch. The wiping solution used is 10% NAPA water-soluble oil. That does leave a light coating of oil in the bore. Also, excellent accuracy has been had with PP bullets when the patches are lightly coated with sperm whale oil. I'm sure any decent oil will work. For a while, my bullets were dipped in a specially formulated lube and then cookie-cuttered using an appropriately expanded case to remove excess lube.

I found that if I did not dry the bore, accuracy fell off. That's what I was doing when first shooting Creedmoor matches with PP bullets back in 04. Testing showed that removing all fouling and drying the bore produced the best, most consistent accuracy.
All the best...DanT..."The nation which indulges towards another a habitual hatred or a habitual fondness is in some degree a slave.” - George Washington’s 1796 Farewell Address
bruce m
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Re: Random Lube & Fouling Ruminations

Post by bruce m »

orville,
my take on what sharps said is not so much that it was better to oil the bore or not to oil the bore, but that if you do it is important to be consistent in how you do it.
some of the odg carried a number of rods to carry out all the wiping functions they thought necessary, and one of these was to wipe after oiling, so there was just the barest film of oil left in a consistent manner.
they must have taken it in turns to shoot, as we would not have the time to wipe how they did, say 20 mins at the creedmoor cup.
the beauty of the grease wad is that it combines with powder fouling to make soap, which when combined with water in wiping makes the water wetter, thus cleaning more efficiently.
cutting oil contains a soap or detergent which does the same thing.
consistency in all things leads to accuracy. how you achieve it comes from much experimentation.
keep safe,
bruce.
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desert deuce
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Re: Random Lube & Fouling Ruminations

Post by desert deuce »

And then along comes single digit humidity and ambient heat at barrel level above 120 F with radiant heating that can, without firing a shot, make the rifle barrel so hot it is difficult to grasp as you watch your favorite xyz lube vaporize before your very eyes.

Sometimes the trick is to have some lube stay on the bullet long enough to get the round chambered.

And after all that it gets hot. :shock: And, once in a while you see the steam off the wet patch as you push it out the muzzle then pick up the crispy dry patch a few minutes later which is exactly why The Creedmoor Cup is shot in March.
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gunlaker
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Re: Random Lube & Fouling Ruminations

Post by gunlaker »

I've been reading a bit about boundary lubrication today. Other than learning that really we are running into an issue of surface roughness ( asperites ) and that loads are supported by a combination of thin fluid films and asperite contact, I've learned that boundary friction is pretty complicated. It does seem that you want polar lubricants as I've read in a couple of sources. I also learned that Porpoise Jaw Oil is excellent :D

I am definitely intrigued by statements that some lubes provide better accuracy than others, even when leading is absent.

If surface roughness is a major factor, and thus barrel smoothness is good, what about bullet smoothness? Some moulds definitely make smoother bullets than others. This probably makes for less asperite contact and more fluid contact.

Also with respect to wiping fluids, I imagine you want minimal surface tension.

DD, I thought that in Arizona you wet the patches so they don't light on fire before you get a chance to use them. :lol:

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Re: Random Lube & Fouling Ruminations

Post by boge »

Yet, is not even a minute amount of soluble oil left in the chamber conducive to case stretching? It seems extreme to have to run a patch into just the chamber after all the wiping/drying to eliminate the last trace of it.
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DanTDesigns
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Re: Random Lube & Fouling Ruminations

Post by DanTDesigns »

gunlaker wrote:I've been reading a bit about boundary lubrication today. Other than learning that really we are running into an issue of surface roughness ( asperites ) and that loads are supported by a combination of thin fluid films and asperite contact, I've learned that boundary friction is pretty complicated. It does seem that you want polar lubricants as I've read in a couple of sources.

One of the reasons that rendered animal fat works well as a BP lube component is because it is a polar lubricant. Long-chain carbon polymers are also polar lubricants. Years ago JR (alterfurz) started using neopentyl polyol esters in his Lube-of-the-Month concoctions with considerable success. These esters are also polar lubricants. Based on research years ago, I pondered putting a positive charge on the barrel to further enhance lube adhesive to the steel. If you see me shooting with wires attached to the barrel, you'll know what I'd doing:-)))

I am definitely intrigued by statements that some lubes provide better accuracy than others, even when leading is absent.

During extensive lube testing years ago, some lube concoctions produced better accuracy than some others, even though there was no leading or hard BP fouling in the bore. During those series of tests, all load components were held constant except for lube. At the time I thought that the accuracy differential was a function of more consistent MV and also that the MV mean was better tuned to the rifle's barrel harmonics. All loads were shot over an Oehler P35. There were MV differences between lubes. I'd have to look at my spreadsheets to post some of the MV differences.

Also with respect to wiping fluids, I imagine you want minimal surface tension.

Yes, I agree that minimal surface tension is probably a good thing in a wiping solution. Also, and maybe even more important, we want a wiping solution that is highly efficient at dissolving BP fouling so the patch can absorb it.

DD, I thought that in Arizona you wet the patches so they don't light on fire before you get a chance to use them. :lol:
You've got to be a desert rat to shoot in AZ when the temps are up and humidity down. DD is a Desert Rat par excellence.

Chris.
All the best...DanT..."The nation which indulges towards another a habitual hatred or a habitual fondness is in some degree a slave.” - George Washington’s 1796 Farewell Address
bruce m
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Re: Random Lube & Fouling Ruminations

Post by bruce m »

I have noticed that many guys use patches only damp.
I use them very wet, preferring to use cutting oil rather than plain water, as it protects from rust.
could wetter patches help cool the barrel a little?
I also use bore pigs really wet,.
do damp patches have an advantage over wet ones?
keep safe,
bruce.
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Re: Random Lube & Fouling Ruminations

Post by Orville »

I have used damp to wet patches but lately I have been looking at the last patch before I run the dry one. I'm looking for a consistent condition of the patch if I don't see what I want then I'll run a third or fourth patch. I'm looking at it when it come out of the muzzle before pull the rod and drop it off. If it is really hot and dry and if I feel it is not getting tha fouling in the last 6-8 inchs of the barrel I will short stroke the rod in that last 6-8 inchs.
I turn may own jags so there is a good fit with the patches I'm using, and it may not work with a different brand of patches.
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SchuetzenDave
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Re: Random Lube & Fouling Ruminations

Post by SchuetzenDave »

For both smokeless and black powder some of us choose bullets with more grooves and wider grooves that provide more lube.
Lots of lube mixes with the fouling and helps the driving bands wipe the barrel clean in addition to reducing friction.

Twenty years ago I measured the width of grease grooves as well as counted the number of grease grooves to select the moulds I would use.
That was when I selected and started shooting Paul Jones Moulds.


lube groove widths of my caliber molds:

Accurate Molds: .065"
Boomer Molds: .065"
Lyman Molds: .045"
Paul Jones Molds: .085"
RCBS Molds: .065"
SAECO Molds: .040"
Winchester Molds: .050"

Many people have been successful shooting Paul Jones bullets using both black powder and in the Schuetzen game.
I believe it was in part due to the lube supply provided by his bullet.
I hope some of the other mould makers pick up from Paul Jones experience of making moulds.
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Re: Random Lube & Fouling Ruminations

Post by DanTDesigns »

SchuetzenDave wrote:For both smokeless and black powder some of us choose bullets with more grooves and wider grooves that provide more lube. Lots of lube mixes with the fouling and helps the driving bands wipe the barrel clean in addition to reducing friction....
Gents,

When first starting out in the BPCR games, I noticed the Oehler P35 was collecting lots of lube chunks. The rifle's muzzle also had a build-up of lube (lube star.) That's when the idea of "Just Enough Lube" started to germinate. And, the more lube a bullet's lube-grooves hold, the more drag produced by the lube grooves due to the width and depth of the grooves. As a result of those initial thoughts, I embarked on a 10 year odyssey to ascertain what the optimum trade-off was between lube-carrying capacity and BC robbing drag caused by the lube grooves.

This optimization becomes more important as the ranges shot as well as wind increases. For Creedmoor matches, the difference in drag/wind-deflection between a 45-cal, Paul Jones Creedmoor and Money Bullet, both weighing 540 grains is substantial. Part of the difference in drag is due to the nose and part is due to lube-groove drag. The difference between just the lube grooves of the two bullets is about 8 MOA of elevation in favor of the Money Bullet lube-grooves when both bullets are fired from the 1,000-yd line. That is not trivial. My guess is that just from the lube-grooves the PJ Creedmoor bullet requires about 15% more wind correction. If just plinking or busting rocks, no worries. But, when firing from the long lines and wanting to run with the big dogs every bit of improved BC helps.

From my findings, I feel comfortable with stating the following:

1. Stainless barrels require less lube than chromoly barrels all other things being equal. Bullets that work in stainless barrels can cause terrible leading in chromoly barrels.
2. Lube efficiency makes a difference with respect to how much lube is required.
3. Lube groove location makes a difference in how well the lube controls lead and/or powder fouling.
4. Barrel length also dictates optimum lube-carrying capacity.
All the best...DanT..."The nation which indulges towards another a habitual hatred or a habitual fondness is in some degree a slave.” - George Washington’s 1796 Farewell Address
gunlaker
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Re: Random Lube & Fouling Ruminations

Post by gunlaker »

I'm going to do a little reading to see how the length of some of the long chain polymers are relative to the average dimensions of the surface roughness in a barrel. That could be interesting stuff.

Chris.
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Re: Random Lube & Fouling Ruminations

Post by bruce m »

dan,
point no 3 about lube groove location is not clear to me.
could you elaborate on that please?
keep safe,
bruce.
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boge
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Re: Random Lube & Fouling Ruminations

Post by boge »

DanTDesigns wrote:
SchuetzenDave wrote:...I embarked on a 10 year odyssey to ascertain what the optimum trade-off was between lube-carrying capacity and BC robbing drag caused by the lube grooves...
And it's a fact that the lube capacity is not a static number that includes all climates & conditions. Agree?
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