Lube Purging

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  • Last Post 18 November 2018
frnkeore posted this 19 September 2018

Tell me about it. How and why does it effect accuracy or, is it real, at all?

Frank

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Ken Campbell Iowa posted this 20 September 2018

... i understand that lube purging ... is where the gun shoots fine but after so many shots shoots a wild one or two ( purging excess lube ) ... the shoots fine again until another lube purge is called for ...

"" oh it's purging time again ... yer gonna leave ( the group) ... ""

....can anybody think of an experiment where we could get a better handle on " lube purging" ... ...

as usual, everytime we change something to prove our point, the changes themselves confuse the experiment ...

if we increase the groove volume to hold more grease, the bullet is less supported ...  2000 shots later, we need to then cross check the effect of wide grooves but with less grease .... 2000 more shots ....  then maybe wide grooves with harder lube against softer lubes ... 

we might forever be doomed to johna's * pretty sure *  that lube purges ..... or doesn't purge ...

*************************

maybe we could pre-coat the barrel with more and more lube and see what happens ?? ...  how can even a really really greasy bullet over-lube a barrel ?? .... maybe the waxy grease crystallizes and actually de-conditions/cleans the barrel erratically ....   turning it into a " cold barrel " that needs a fouling shot ( flyer )  ..to return to group center ....

another mystery of cast bullet shooting .  yet another ....

ken

 

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Ross Smith posted this 20 September 2018

Why would we cure this? We (I) need some excuse for "flyers".

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John Alexander posted this 20 September 2018

I brought up lube purging.  I didn't mean to imply that I believe it is real.  Highest and best use may be as an excuse for those dreaded flyers as Ross suggests.

John

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frnkeore posted this 20 September 2018

John,

No I didn't think that. It's something that I've heard of for 10 years but, I don't remember reading anything factual about it. 

I open this to see if there was anything factual or at could be proven, regarding it.

Frank

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4060may posted this 21 September 2018

FS 116 and 120, has article about purging

Chuck

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Ross Smith posted this 21 September 2018

Why would lube accumulate in the barrel? Doesn't it get "purged" every shot by the gas check if not the driving bands? Something else must be influencing this, rough barrel, leading,//////////?????????????? Just thinking.

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4060may posted this 21 September 2018

Merril Martin did a long dissertation on it with 22lr in Precision Shooting, I give away all the Issues I had to a 22lr bench shooter....

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frnkeore posted this 21 September 2018

I don't have FS 116 & 120. If someone could read them and give a summery, it would help.

I'm at odds of how it could be documented. Maybe high speed photos?

It seems hard to believe that any kind of lube, could deflect a lead bullet or does the accumulated lube, cause the bullet to ride over it, inside the barrel?

Frank

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Larry Gibson posted this 22 September 2018

Some are of the opinion that "lube purging" is the purging (throwing off or spinning off) of the lube out of the lube grooves on exit from the muzzle during flight.  It is believed if the lube purges off the bullet it should do so immediately and evenly otherwise unbalancing of the bullet may occur during flight which, of course, can adversely affect accuracy. Additionally the harder wax lubes may have a "vaning" effect also. 

LMG

Concealment is not cover.........

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Brodie posted this 22 September 2018

And Boys and Girls that is where the "Lube Star" on your muzzle comes from.

B.E.Brickey

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fa38 posted this 22 September 2018

I think lube purging was a theory put forth by Tom Gray a number of years ago.  He also experimented with making various lubes and believe the final one was Gray 24.

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Larry Gibson posted this 22 September 2018

The subject was also heavily discussed in the HV/RPM threads on the other forum.  The subject was broached when I found a large amount of different lubes being "purged" and ending up on the chronograph screens.  It most was the harder lubes used in older design bullets with large lube capacity grooves.  It was prevalent with both 6.5 and 30 caliber bullets.  The depositing of lube on the screens ended with bullets of better design and the use of softer lubes such as NRA 50/50, 2500+ and the original Javelina.

Here is a photo of the screens I took back then (10 +/- years ago).  Yu can plainly see the lube splattered on the front of the screens.  The little bits and pieces splattered all over all 3 screens indicates the lube is not "purged off the bullets at the same time nor evenly. 

 

LMG

Concealment is not cover.........

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frnkeore posted this 22 September 2018

So then, are we saying that lube purging, is simply the normal ejection of lube, when the bullet exits the barrel?

If so, how can it effect accuracy, unless all the lube doesn't leave the grooves?

Is it a misnomer then?

Frank

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shastaboat posted this 22 September 2018

Like Old Coot says you know things are right if you have the lube star on your rifle's muzzle.

 

Because I said so!

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frnkeore posted this 22 September 2018

The context that I'm speaking of, is that it detracts from accuracy. That is how I hear it referenced.

"a flier, because of lube purging"

 

Frank

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Brodie posted this 22 September 2018

Whether or not ejection (through centripetal force) affects accuracy it still makes a mighty fine excuse for what the nut holding the stock caused anyway.

B.E.Brickey

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fa38 posted this 23 September 2018

I am assuming that Frank was asking about fliers from too much lube inside the barrel and not the bullet having lube flying off after it leaves the barrel.  Tom Gray wrote about it in a couple of the FS issues.  A couple of photos from FS 116 and 120

 

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frnkeore posted this 23 September 2018

Thank you, very much fa38.

He doesn't say how that he proved his purging theory or exactly how it causes fliers. Is there more that explains that? He talks like it's been proved somehow. Or does he just say in the article, that his lube prevents lube purging?

It seems to me that he's talking about the bore condition, being consistent and I would agree with that, if it could be proved that it effects the bullet (damage), velocity (high or low impact) or barrel harmonics but, how has he proved that fliers are a result of to much lube, it seems that, if your considering inconsistent bore condition, being the cause, to little lube, could also be the reason. I would think that to little lube could rectify itself easier than to much.

If the purging, causes a flier, how does to much lube rectify itself, especially with a PB bullet. If a GC scrapes the bore, in the purging, why wouldn't the GC, prevent it, in the first place, when less lube is present?

It's still unclear what it might be.

Frank

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fa38 posted this 23 September 2018

Here are the entire articles from FS116 and 120.

Probably have to get your reading glasses for the photos.

 

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fa38 posted this 23 September 2018

 

My lube flyer picture of two groups from June 1996. 

Top group was shot with my lube, probably a mixture of bees wax, lanoline, a couple sticks of the 50/50 beeswax and alox, peanut oil and a stick of LBT blue soft for color.  It turns to a light green color.

The bottom was shot with Gray 24.  The two flyers were something like the 5th and 9th shots.  I shot the extra two to see what would happen.  I was going to cut the flyers out and show them to a friend but decided to keep all 12.  The rifle was a Peregrine chambered in a long neck, short body 30 Herrett that I no longer own.

I shot other groups with Gray 24 and decided to quit using it because of the occasional flyers and I could make my lube a lot cheaper than purchasing LBT or Gray 24.  I sold the rest of the Grey 24 to Fred Sinclair.  That does not mean I did not get fliers with my own lube and maybe all my fliers are operator induced.

Ninety percent my shooting at that time was with single shots and plain base bullets at velocities from 1000 to 1500 fps.

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Tom G posted this 12 November 2018

I'm the Tom Gray who discovered that too much lube will cause fliers.  And, for lack of a better term, called it "lube purging".  This was quite a few years ago when I was shooting the CBA benchrest matches.  You can argue the cause all day long as we really don't know for sure what's happening inside the barrel when a lead bullet with lube is fired. But, the effect of too much lube can be seen and it's for real. 

The way I found it was when I was shooting a loverin style bullet with lots of lube grooves. I had a very accurate benchrest rifle where you could see some of the more subtle effects when changing different things with the load.  With too many  of the grooves filled with lube there would be a quite predictable unexplained flier in just about every 10 shot group. 

Just for the heck of it I tried reducing the amount of lube on the bullets by wiping out the lube from the lube grooves and eventually with just a couple of grooves filled, the fliers went away. Figuring that I was getting too much lube in the barrel I repeated the test several times and with different guns,bullets and different types of lube and the results were the same.  

It turned out that there was an optimum amount of lube on each particular bullet design to eliminate these unexplained fliers. This was a simple thing to test if you had lots of lube grooves and could get more than you needed on a bullet. It's something that is easy to do. Just take your particular bullet and start reducing the amount of lube and see what happens. If you go too far, you may get leading. Clean the gun and start over if that happens. To see how the barrel is doing, look into the muzzle end of the barrel and see if there is any light flash of what I called streak  leading near the end of the barrel.on top of the lands.  If there is, the bullet probably ran out of lube before it ran out of barrel. So you have found what is too little lube for that barrel/load combination. I found that about .4 grains ( that's 4/10ths of a grain of  lube by weight,)  worked best in my benchrest rife with a tapered throat and a identically tapered bullet that fit the throat with a slight interferance fit. If a person has a sloppy bullet fit they may never see the difference as there is so much blow by on the bullet before it seals in the bore that they blow the lube off the bullet before it goes down the barrel. If that's the case, you won't see the lube fliers in the big groups that will result.  

You can argue cause and effect of fliers and they can occur for a lot of reasons. You will find folks who do tests that won't show the subtle effects of too much lube. If their rifles and bullets don't have the accuracy potential to really see the cause and effect they well poo poo the theory as they can't see it in their groups. In other words, it the bullets are bad and the barrel is bad and the bedding is bad or other things like poor bullet to throat fit are causing a lot of fliers it's too hard to see a subtle thing like a flier caused by too much lube. I.O.W. you have to have a test bed that has the accuracy potential to see the difference that the amount  of lube makes to the groups. If the gun shoots all over the place, the shooter won't see the fliers that are in the groups caused but too much lube. 

In summary, If you have a bullet that has a lot of lube grooves, you probably don't have to fill them all up. I've found that you can have too much lube on bullets and it will cause fliers. I first did these tests and got the lube fliers using the old NRA alox formula. Different lubes have different effects as far as causing fliers. During my lube testing I found that lubes that had parafin wax as a base caused more lube purging than formulas that had other types of waxes. The type of wax makes a big difference.  

Your mileage may vary. 

Tom

 

 

 

 

 

 

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Mike H posted this 12 November 2018

Great reply and explanation Tom,I haven’t been up to the level of shooting and equipment to notice the problem,it seems to me that a lot of knowledge gets lost and/or distorted,only to be reinvented later.

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JeffinNZ posted this 12 November 2018

Here is a recovered .310 Cadet bullet with a full load of lube still on board.  Food for thought.

Cheers from New Zealand

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John Alexander posted this 12 November 2018

Hi Tom,

Good to see you back on our forum. Many of us would like to see you back winning CBA matches again, In someone else's class of course.

Hope all is well there.

John

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frnkeore posted this 12 November 2018

Tom G,

Does the velocity of a bullet effect your theory of lube purging?

Will single lube groove bullets always be more accurate than multi-groove bullets?

Does groove depth also effect the purging fliers?

And from what your saying, you don't actually know why the fliers occur, just that to much lube causes it.

I ask, because the term, "lube Purge" suggests that there is to much lube in the barrel and that at some point, the bullet is able to push excess lube out (causing the flier) and restore a stable condition.

Do you have any idea of what barrel condition causes the flier and why it returns to a more stable condition?

In addition, spitzer bullets,shot breech seated at 1400+ fps, using about 4 lube grooves, don't seem to be effected very much, by this purging thing.

Thank you,

Frank

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Ross Smith posted this 12 November 2018

I sort of owe Tom G. an apology. My comment on lube purging was tongue in cheek but after watching this thread and Tom's last post I now get it. I was-am guilty of over greasing my bullets. So now I'm playing with less to see how that works.

My current attempt is to use bullets dipped in warmed 45-45-10 for just the bottom 1/4 inch. It only has 1 lube groove anyway but this way only lower part will have a thin coat.My usual carnuba red lube is I think too much. I'll let ya know tomorrow.

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RicinYakima posted this 13 November 2018

Ross, My hypothesis is that you only need enough lube to vaporize between the ignition of the cartridge and the bullet exiting the barrel.  The mechanical lubing is not really a factor. BUT we don't have a good handle on pressure, temperature and mechanical factors. I just know that when I changed to Grey #24 lube and started lubing only the space above the gas check, my off shots got less. But that may just be my 70 something hand shaking less! Ric

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Ross Smith posted this 13 November 2018

RicinYakima and or Tom Gray: How -where can I get some #24 lube? I had some good results just lubing the gc gap with carnuba red. Wish I had paid more attention now, I was more interested in leading and I just "sent" 10 shots down the barrel and checked for leading. 

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RicinYakima posted this 13 November 2018

Sorry, Tom hasn't made lube in years. I have enough to last awhile, but maybe you can talk him into making more.

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Ken Campbell Iowa posted this 13 November 2018

Dan Lynch says we need some grooves.  ( ? place for the displaced lead to go, otherwise finning at the base ? )

Merrill Martin says that grooves filled with non-compressible grease aren't grooves anymore.

Tom Gray says that filling all/most/more than one of the grooves results in more flyers.

*************************

maybe filling too many grooves reduces the number of grooves necessary to stop the finning .

*****************************

Gary mentions that nose-rider bullets really shouldn't shoot real good ....  but in practice they seem to be a good way to get 1.4 moa from a factory chamber.  Lyman 299, most Saeco and RCBS are easy to get shooting well enough.  oh, and Nat. Champ ( x N ) JohnA and his long bore-rider 22 .   

could it be that nose-riders, even though they probably do slouch sideways unevenly down the barrel ....  more than make up for it because they don't fin as much ?? ....    

could it be that gas checks mostly make a little final groove to catch swaged lead ?

********************

while thinking about this, consider that Lapua, who obsess over extremely good Ammo .... make a lead match bullet with longitudinal grooves .......  

think i will try longitudinal grooves on JoeB's naked bullet ... as soon as i figure out how to do that ...drive nails through the sides of a lee sizer ?? ...

ken

a

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4060may posted this 13 November 2018

Ken

There was a company making knurled bullets for the Schuetzen crowd, minimal lube...try knurling the naked bullet, might start another JoeB search

 

Chuck

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frnkeore posted this 13 November 2018

Those bullets were made on the East Coast, in the NY area, I think.

They were knurled, lubed and then swaged. Someone in that area held a ASSRA record, using them. I don't know if it still stands though and I don't know if they are still being used as, I don't see them listed in equipment listings.

They were quite expensive and maybe that's why.

Frank

 

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Ken Campbell Iowa posted this 13 November 2018

expensive ... hey i looked up mj benchrest bullets recently ... 70 cents a bullet ??   making $120 for an * Accurate ... ...  NOE ... Mountain ... etc.  *  .. custom mold look pretty good ...

at 20 shots at a coyote, it would cost $14 just for Bibs mj bullets alone ... geeesh ...

ken, who looks for bargain primers and powder at estate sales ... 

 

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Brodie posted this 16 November 2018

I have a question: Does the excess lube, prior to purging, cause fliers by squeezing the bullet down by the actionof the lube already in the barrel?  The lubes are in a semi-solid-liquid state as the bullet rides over it .  Would a non-compressible fluid (which at that time the lube may very well be) by taking up space between the bullet and the barrel squeeze it down somewhat possible causing the bullet to not fly straight upon exit.

What ya all think?

B.E.Brickey

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John Alexander posted this 16 November 2018

Brodie,

I don't know the answer but I have read, on this forum I think, of retrieving bullets from a snow bank (or other) that were under bore size.  Have no idea it that could have any connection to lube purging and such.

John

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frnkeore posted this 16 November 2018

Brodie,

I think if what your suggesting is true, each succeeding bullet would get deformed more, since it would be getting smaller and there by releasing, even more lube and more fliers.

I just can't find a way of understanding this concept, of how that if the lube causes it, that shooting more lubed bullets will bring a better condition back.

Frank

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4060may posted this 16 November 2018

Frank

Somewhere back in the memory bank, 1990-1991 or so , Lee shaver was selling a BP lube with a lot of Moly in it, listening to the guys talking that use it, CLAIMED, the build up made the bullets smaller as they shot, don't flame me, I think this is what I remembered, on the downward side to 80

I first saw the knurled bullets at TUSCO, maybe the Coors match, yes, too expensive for me

Chuck

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Tom G posted this 16 November 2018

A long time ago, I tried moly lubed cast bullets and determined that there was no advantage of them over conventionally lubed bullets. I applied it by running the bullets in a vibrational case cleaner with BB's and some moly powder. This kind of beat up the edges of the bullets and I worried that I was damaging the bullets. 

I've shot more than a few thousand of moly coated jacketed bullets ( lead bullets wearing copper condoms) on prairie dogs. They would allow me to shoot several hundred through a barrel without having to clean and still maintain accuracy. The problem was that it does build up in the barrel and when you clean the barrel, it takes at least 15 rounds to get it conditioned to shoot well again. 

I have a Hawkeye borescope and have inspected several of my gunsmith business customer's barrels that shot nothing but moly jacketed bullets. The barrels were so full of moly that it laid in furrows in the grooves like snow would do after a strong wind. These barrels shot pretty well and were never cleaned. All the owners ever did was run a patch saturated with 3 in One oil on it through the bore to keep the barrel from rusting. This suggests that eventually the barrel built up to a steady state of moly and stayed that way. I personally haven't shot enough of the moly'ed lead bullets to ever get to that condition as I also tried shooting them in long range matches that were only around 30 shots total. Since it took so long to re establish the moly after cleaning, My barrel was always changing during the the match and that didn't work out for beans. . 

I eventually, in shooting long range competition, I went to jacketed bullets that I coated with Hexagonal Boron Nitrate. This didn't seem to build up in the barrels and only took a shot or two to recondition the barrel surface after cleaning. Have you thought of using that on cast bullets?

Tom

 

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Brodie posted this 18 November 2018

Frank,  Since you are dealing with essentially a fluid, I hypothesize that the fluid (lube ) builds up until the bore will hold to more (a very small amount) and its own surface tension removes some amount of it upon firing.  Possibly enough is removed upon that firing that the amount of lube has to build up for the next (whatever number of shots) until it is again ejected along with the bullet causing the flier. 

It is something to mull over anyway.  I suppose that you could test it by firing a string of bullets with a paper close to (lets say near ) the muzzle but not close enough to be destroyed by the muzzle blast.  You could even put a hole in the middle large enough to see the target through and see if lube is caught on the paper when the flier occurs. 

B.E.Brickey

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BigMan54 posted this 18 November 2018

I have 2 old Loverin molds. A #287405 & a #311467, my old man told me to only lube the bottom 4 grooves. 

Now I know why.

Thanks, Guys 

Long time Caster/Reloader, Getting back into it after almost 10yrs. Life Member NRA 40+yrs, Life S.A.S.S. #375. Does this mean a description of me as a fumble-fingered knuckle-draggin' baboon. I also drool in my sleep. I firmly believe that true happiness is a warm gun. Did I mention how much I HATE auto-correct on this blasted tablet.

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