Abrasion of PaperPactch on the Bore?

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  • Last Post 27 May 2018
CB posted this 16 May 2008

The following are replies from Topic 'paper patch 45/70' between RD & Pete, referring now to a new topic concerning abrasion of paper. Any other inputs welcome.  Pete:

"  I kinda like the way your bullets are lubing up. For me one of the things about PP'ing is the erosive nature of any kind of paper you'd use."

Never heard that paper patching causes erosion. Where can I find documentation for this?

RD


Rd,

  Proof, as far as I'm concerned comes from personal experience. I've got a .45/70 Navy Arms Roller that I've shot several thousand rounds thru. When I got the gun you could see the reamer marks on top of the lands. Now that nore is as shiny and free of marks as a mirror.

  For 30 yrs. I also worked n the valve business. In the paper making process paper slurry is considered to be about the most erosive mix there is.... and this has a high percentage of water to dampen the action. 17-4PH was especially developed to stand up to this slurry mix. Plain steel or stainless steel valves will erode out in less than 6 months. 17-4PH valves will stand up longer but are not immune to this erosion.

  So I would say that altho slurry moves thru the pipes at a good clip it's no where near as fast as as bullet going thru a barrel. Modern steels will hold up longer than the old soft steels of yesteryear but aren't immune.

  Without proof I would say that if a good lube can be put between the bullet and barrel so much the better. Just like it's better to put a lube between a standard GG bullet and the barrel. We all know what happens when you don't, or the lube fails to do it's job.

PETE


Pete: 

I have seen the question of what  effects PP has on modern gun barrels come up occasionally. And it seems that no one has any definitive answers. At least that I have seen. I think that the abrasiveness of some types of paper is pretty well established. It can be used to polish a barrel before blueing or a gunstock finish and dull cutting edges.  And, PP does polish a bore over time as do lead bullets.  A shooter friend's son is in the paper industry. And as I understand it, the composition of different types of paper can vary a lot. From various mixtures that use clay as a filler to 100% cotton bond which has no fillers. 

Erosion and abrasion are two different processes. The questions seems to be, is this abrasion significant over the normal life of a rifle bore? And, do different papers have different abrasion levels? I for one, certainly am not going to intensionally shoot out anything that is going to erode the bore. However, abrasion is another animal. So, I use nothing but 100% cotton bond for PP.

This should probably be a separate topic and I would be interested in hearing more on this subject. 

RD   

 Last edited on Fri May 16th, 2008 03:01 pm by R. Dupraz

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runfiverun posted this 16 May 2008

from what i have seen and also heard paper will wear out a bbl

faster than a plain Pb bullet.   is it any faster then a jacketed bullet?

maybe, i think so..              my opinion.

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CB posted this 17 May 2008

I don't have anything new as far as BPC rifles so I don't know about them. I have read about original rifles having shallow rifling. I have an old 40 caliber of the time period of PP and it only has .0035"-.004” deep grooves. (maybe it's is worn out?)

Maybe shooting paper patch CBs in a deeper grooved rifle, say .006” deep grooves would put more pressure on the top of the lands, causing higher friction and more abrasion?

From what I've read about patch paper, I think a high quality paper containing linen is the best. Don't know if linen is any less abrasive than cellulose (wood), so maybe it is something else contained in the paper mix that is abrasive?............my two cent's worth...................Dan

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PETE posted this 17 May 2008

 My use of the word erosion was not the right word and should be abrasion as RD mentions. My apologies!

  Also as mentioned different papers will abrade faster than others. Especially those with a high clay content. My experience has been with 100% cotton bond paper only.

  As Dan mentions, I don't know exactly why PP's wear a barrel. If I was guessing I would say it's the lack of enuf lube between the paper and the bore. Altho I do use a thin film of lube, as mentioned, I still noticed the wear on the Navy Arms RB. Some advocate not using any lube at all which I would think would wear a bore even faster. Plus all the old PP cartridge makers used some kind of lube. This is why I was thinking that Norm's way of patching GG bullets and then running them thru a lubri-sizer might cut down, or eliminate, this abrasion factor. Something to try out with a long term experiment to see, and certainly can't harm anything.

  The use of a deeper rifled barrel was proven a long time ago by the manufacturers to not be correct. In fact rifles made today are about a .001” or two deeper than original guns made to shoot PP exclusively were. The problem with going to a deeper rifling is that you then have to go to a thicker paper. You must have paper at least thick enuf that when it goes down the barrel the lands can't cut completely thru or you'll get Leading.

  As runfiverun alludes to..... paper patches will wear a barrel out faster than GG bullets. Actually there are recorded instances of rifles with over 150,000 rds thru them with GG bullets and no sign of wear or degradation in accuracy. I sometimes wonder about the veractiy of this statement (hard to question Uncle Harry) as BP and the early smokeless powders were not especially kind to barrels unless religiously cleaned immediately after shooting. With the corrosive primers thrown in it's a wonder any barrel could be shot 150,000 times and survive the experience.

  I think the wearing out of barrels from using jacketed bullets is due more to erosion of the throat. I've seen sectioned barrels and it's a wonder you could get any accuracy at all from them considering how ate away the throat was. 4 or 5” ahead of the throat the barrel looked normal.

PETE

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CB posted this 27 March 2009

100% cotton paper does indeed contain inorganic fillers.  The “percent” of cotton is given as part of the fiber furnish, not the total furnish.  Depending on the manufacturer, the filler content is likely 12-18%, and could be in th 20-22% range.  The filler may or may not be clay.  Filler clay, as the inorganic component, is used in the acid papermaking process.  If the paper is made in an alkaline process, the filler is calcium carbonate (CaCO3).

The cotton content refers to the amount of cotton linters which is used to in the furnish, or fiber blend, to make the particular grade.

FYI:  “Linen,” when referring to the fiber, means the paper contains flax fiber-which is very strong.  “Linen,” when referring to the finish, or surface of the paper is merely an embossed pattern pressed into the already-made sheet for esthetics/marketing, not for function.

I posted a tutorial about paper properties on castboolits.com, called “Paper 101.” The purpose was to address some points about paper and some of its properties (including abrasion, chemical and fiber properties etc) that relate to selection/use for paper patching bullets. 

http://castboolits.gunloads.com/showthread.php?t=34782>http://castboolits.gunloads.com/showthread.php?t=34782

 

 

 

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AMMOe posted this 27 March 2009

In my very limited experiences rebarreling a couple of Sharps rifles that had been used exclusively with black powder and paper patching, it is the combination of the hard BP fouling and the paper that causes barrel wear. The pair of Sharps I rebarreled had striations running on top of the rifling lands that were visible with the naked eye. The owner said that both rifles were smooth and shiny for the first couple of hundred rounds and then they started to dull, then showed visible wear/abrasion. I have no clue as to the paper type or any other specifics but from what I saw, it sure looked like someone had swabbed the barrels with fine sand paper for patches. Just an uneducated view. ~AMMOe

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.22-10-45 posted this 05 March 2010

hello, I spent 11/2 shooting seasons shooting nothing but paper-patched bullets thru a Shillen barreled Sharps-Borchardt in .22Hornet and a Ruger #1 in .222Rem. the Shillen is a match-grade chrome-moly that I spent extra money on for hand-lapping. I thought that barrel was smooth. After firing around 200 rnds. of paper-& some with teflon tape, now it is smooth. Wheras before, 1st. patch wet with Hoppe,s(nitro-benzene added..Bruno Shooter Supply) came out black, took 4-5 patches to clean up. Now 1st. patch black, 2nd. wpatch comes out looking as went in, dry patch comes out snow white. Bore dazzles when held to light. Kind of glad I concluded test when I did, might have ended up with Sharps smoothbore. Glad to see all the experimenting going on guys, also glad I finally got on sight.

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.22-10-45 posted this 05 March 2010

hello again, I forgot to mention that all bullets were lubricated over patch, most were moly-coated,some teflon sprayed as per Mr. Harris instructions from the 70,s. even on the moly-coated ones, these were hand lubed by rubbing in with fingers a sofer version of my standard black-powder & smokeless lubes.

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Reverend Recoil posted this 30 March 2010

I keep a data book on my AR15 service rifle and log the number of shots fired after each match and practice session. I plan on replacing its barrel after 3000 to 3500 shots. That's a new barrel every fourteen months.

Is gas erosion worse than paper patch frictional wear? Until someone demonstrates and documents paper patch barrel wear with real data the world will never know. Routinely slugged your barrel and recording the measurements after every 500 shots may be a good place to start. I use paper patch bullets with my hog hunting rifle. I don't think I will ever kill 2000 hogs in my lifetime. So far it's been only one shot per hog. Somebody else can re-barrel that rifle.

Barrels are an expendable part of rifle shooting. Put 20¢ in a pickle jar for every shot fired and you will finance the replacement of a worn barrel.

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delmarskid1 posted this 09 April 2010

I love wearing out barrels by any means possible. It means I'm shooting.

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303Guy posted this 13 June 2010

Mmmmm..... I would like to see someone patch up so many boolits to wear out a barrel!/forum/images/emoticons/134.gif

Seems to me that paper patching is a way to make worn or rust damaged barrels shoot straight again.

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argie1891 posted this 13 June 2010

For a test take a piece of paper and rub hard as you can on the blue of your blr. i would bet that you would wear out your hand before you could harm the steel of the blr. as a matter of fact i bet it would take quite a while to harm the blue. you rub the blue with paper and report on how long it takes to remove it. joe gifford

if you need me I will be at the range

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buttstock posted this 26 May 2018

100% cotton paper does indeed contain inorganic fillers.  The “percent” of cotton is given as part of the fiber furnish, not the total furnish.  Depending on the manufacturer, the filler content is likely 12-18%, and could be in th 20-22% range.  The filler may or may not be clay.  Filler clay, as the inorganic component, is used in the acid papermaking process.  If the paper is made in an alkaline process, the filler is calcium carbonate (CaCO3). The cotton content refers to the amount of cotton linters which is used to in the furnish, or fiber blend, to make the particular grade. FYI:  “Linen,” when referring to the fiber, means the paper contains flax fiber-which is very strong.  “Linen,” when referring to the finish, or surface of the paper is merely an embossed pattern pressed into the already-made sheet for esthetics/marketing, not for function. I posted a tutorial about paper properties on castboolits.com, called “Paper 101.” The purpose was to address some points about paper and some of its properties (including abrasion, chemical and fiber properties etc) that relate to selection/use for paper patching bullets.  <url=http://castboolits.gunloads.com/showthread.php?t=34782>http://castboolits.gunloads.com/showthread.php?t=34782      

I agree  with this post.  That’s because I wrote it on castboolits.com on a thread called “Paper 101”.  I go by “ catboat” over there.
To write that “paper is abrasive” is not accurate enough.  “ Paper”  can have inorganic filler content   from very low (<4%), to medium content (10–16++%), to high filler levels (>24%+++).  The higher the ash/filler content, the greater the potential for abrasion. Tracing paper is low ash/filler content.  This is due to the desire for the paper to have minimal opacity ( generated by high surface area fillers like CaCO3 and TiO2 ), so you could “trace” an image through that paper.  This would be on the low-end of the abrasion risk spectrum.
So, just saying “Paper is , or is not abrasive...” is too generic.  Define the ash content first, then have the discussion.  I used to work on paper machines.  Smaller machines had round slitters on them to trim an inch or so off the edge of the endless sheet of paper.  They look like pizza cutting wheels.  They have to be replaced regularly, as the medium-high filler level paper dulled them, due to abrasion. When dull, the slitters had a greater chance to tear the paper ( and cause a production-reducing break on the machine ( not good for profits).
Bottom line, to minimize the degree of a paper patched bullet’s abrasion wear on a barrel’s bore, use low-filler content paper.

 

 

 

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Brodie posted this 27 May 2018

Yes paper is abrasive, but so are peoples hands, just look at the railings at any public attraction in the country.  Those pipe rails have been polished to a very smooth surface by the tens of thousands of visitors waiting in line.  Well, the dust and fine dirt on our hands polished them, not the skin itself.

I have used this property of paper (the ultra fine polishing) to shine up some fairly rough bores.  Case in point is a Zastava mini mauser in 7.62x39 which came new with quite roughly cut rifling.  Shooting paper patched bullets smoothed it out and has shined it up nicely.

B.E.Brickey

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