View Full Version : How Tough is Chrome Lining?
I have read that chrome lining is extremely tough and that is why bores and chambers are chrome lined. It is supposed to significantly increase barrel life.
On the other hand, you hear warnings to not be overly aggressive with cleaning rods as you can damage the chrome lining on a chamber and/or bore.
I just wonder, when common sense kicks in, how can a steel cleaning rod cause damage to the chrome lining when steel cased ammo continually rubs the chamber, and metal clad bullets are going down the barrel at great velocity.
Also, if chrome lining on a chamber is damaged (scratched), what would be the effect?
Also, if chrome lining on bore is damaged (scratched), what would be the effect?
Comments on these these questions I have would be greatly appreciated.
Edit: before you respond to this thread, please read post #8 below for clarification of the theme.
You are worrying too much about nothing. Pulling a bore snake through it after every shooting session is all the cleaning a chrome lined barrel needs and more than most of us do.
You are worrying too much about nothing. Pulling a bore snake through it after every shooting session is all the cleaning a chrome lined barrel needs and more than most of us do.
The first part of that is hogwash (at least for the non-lazy) and the second part is sadly true. Precisely why I won't buy a used weapon from anyone.
To the OP, get a carbon fiber or coated cleaning rod like a Tipton or Dewey. Use caution when you clean it and don't be a Cretan and you'll be fine.
dramabeats
08-01-15, 15:30
The first part of that is hogwash (at least for the non-lazy) and the second part is sadly true. Precisely why I won't buy a used weapon from anyone.
To the OP, get a carbon fiber or coated cleaning rod like a Tipton or Dewey. Use caution when you clean it and don't be a Cretan and you'll be fine.
I don't clean my barrel, I see no reason to.
I don't clean my barrel, I see no reason to.
Hey, your investment and $$$. It's a free country, have at it! :D
Straight Shooter
08-01-15, 15:44
ABNAK you are 100% right. To those who see no need to clean a barrel, as was said...its your dime, not mine.
Those steel, issue cleaning rods are, in my mind..an emergency/field remedy. They flex, and over time from extended use can & do cause wear on a barrel. Good one piece rods that are coated are the answer, along with bore snakes too. Ive seen people run rods thru a bore back & forth like they were sawing wood. Slow & steady, using a patch to check when bore is clean. Use quality gear and all will be well.
dramabeats
08-01-15, 15:46
Hey, your investment and $$$. It's a free country, have at it! :D
I'm not losing any money by not doing it, I'm actually saving money :)
I appreciate the resposnes so far. However, I guess my questions in the original post were a little vague. I was giving the chamber and bore cleaning as more of an example of all the stuff you read on the internet about damaging your bore or chamber while cleaning with a steel rod (although I could not find anything where one's chrome lining on the bore or chamber was damaged). I do use a one piece steel rod and sometimes a bore snake.
My main concerns were with regard to how tough chrome lining really is if you can actually damage it with a steel cleaning rod (or a coat hanger on one thread I read), and if it is the chamber chrome or bore chrome is damaged what what would result. Again, I'm not even sure you can damage the chrome lining on the chamber or bore. Many of the internet comments were that damage could occur; however, I could not find any threads showing that the chrome lining was damaged while cleaning.
My common sense (for whatever that is worth) tells me that you would have to very aggressively try to damage the chrome lining of the chamber or bore in order to suceed.
I hope that helps clarify the purpose of this thread.
I appreciate the resposnes so far. However, I guess my questions in the original post were a little vague. I was giving the chamber and bore cleaning as more of an example of all the stuff you read on the internet about damaging your bore or chamber while cleaning with a steel rod (although I could not find anything where one's chrome lining on the bore or chamber was damaged). I do use a one piece steel rod and sometimes a bore snake.
My main concerns were with regard to how tough chrome lining really is if you can actually damage it with a steel cleaning rod (or a coat hanger on one thread I read), and if it is the chamber chrome or bore chrome is damaged what what would result. Again, I'm not even sure you can damage the chrome lining on the chamber or bore. Many of the internet comments were that damage could occur; however, I could not find any threads showing that the chrome lining was damaged while cleaning.
My common sense (for whatever that is worth) tells me that you would have to very aggressively try to damage the chrome lining of the chamber or bore in order to suceed.
I hope that helps clarify the purpose of this thread.
I would think the closer the "damage" was to the muzzle the more inaccurate it could end up being.
I don't clean my barrel, I see no reason to.
There isn't a reason unless you are a paper puncher and a paper puncher isn't using a chrome lined barrel. The guy that builds with a chrome barrel (Like me) is shooting cheap ammo and content with 1 1/2" groups. All of the cleaning in the world isn't going to make it shoot 1/2 MOA! Carbon rods, bore guides and magic solvents aren't going to do anything for me other than waste $$$ I could have bought ammunition with. It has nothing to do with being lazy.
vicious_cb
08-01-15, 16:57
There isn't a reason unless you are a paper puncher and a paper puncher isn't using a chrome lined barrel. The guy that builds with a chrome barrel (Like me) is shooting cheap ammo and content with 1 1/2" groups. All of the cleaning in the world isn't going to make it shoot 1/2 MOA! Carbon rods, bore guides and magic solvents aren't going to do anything for me other than waste $$$ I could have bought ammunition with. It has nothing to do with being lazy.
Unless you think having your barrel last longer isnt saving you money then by all means dont clean your barrel.
Unless you think having your barrel last longer isnt saving you money then by all means dont clean your barrel.
Please explain how over cleaning a chrome lined barrel extends the barrels life?
vicious_cb
08-01-15, 17:45
Please explain how over cleaning a chrome lined barrel extends the barrels life?
So punching your barrel with some solvent every couple hundred rounds is over cleaning?
Never cleaning your barrel is tantamount to abusive treatment. Allowing abrasive carbon residue and debris to stay in your bore WILL decrease barrel life.
dramabeats
08-01-15, 17:46
So punching your barrel with some solvent every couple hundred rounds is over cleaning?
Never cleaning your barrel is tantamount to abusive treatment. Allowing abrasive carbon residue and debris to stay in your bore WILL decrease barrel life.
Pat Rogers is post 45k on filthy 14 and has several other high mileage rifles.
They all still group fine
vicious_cb
08-01-15, 18:03
Pat Rogers is post 45k on filthy 14 and has several other high mileage rifles.
They all still group fine
Testing a barrel at 50 yards does not mean it will perform the same way at 100 and beyond, the article even mentions this. Ask anyone who shots a lot of long range. A shot out barrel may perform just fine close up then falls apart at longer distances.
If you just want a 50 yard smoothbore musket then do what you will, its your dime. I expect my barrels to perform from point blank out to 500m consistently thus Ill will continue to do proper maintenance on my barrels.
An already burnished chrome lined barrel is better served with a chamber brush to remove some fouling related to function. Most users wouldn't noticeably see the difference, unless the precision requirement exceeded it's threshold. For most CL users, I would say a few cranks with a tight chamber brush and a quick push of barrel fouling with a good CLP would be all that is needed for most of us. A precision barrel is another animal altogether. What do you attempt to gain for most by over cleaning?
So punching your barrel with some solvent every couple hundred rounds is over cleaning?
Never cleaning your barrel is tantamount to abusive treatment. Allowing abrasive carbon residue and debris to stay in your bore WILL decrease barrel life.
I didn't think you would have a believable answer. I guess if you thoroughly clean a barrel after every round it will last forever. I am pretty good at math. If it takes $6,000 to wear out a neglected $200 barrel I am good to go with it. I am done. Find someone else to convince your opinion is founded.
SurplusShooter
08-01-15, 19:05
Those steel, issue cleaning rods are, in my mind..an emergency/field remedy. They flex, and over time from extended use can & do cause wear on a barrel. Good one piece rods that are coated are the answer,.
At least for the M1 Garand rifle this is a myth that persists, but has been tested and found to be a false rumor.
The hypothesis that "steel cleaning rods cause barrel wear" was tested by the Garand Collectors Association building a test machine that rubbed a steel cleaning rod down the muzzle end of a M1 Garand barrel. Purposely allowing it to rub up against the sides. The results are that there is no noticeable wear on the muzzle even after thousands and thousands of cleaning cycles.
Firing ammo though the barrel does cause the muzzle to erode (show an increase in muzzle wear measurement). Not the cleaning rod.
(On a Garand they use "muzzle wear" and "throat erosion" gauges to measure barrel life. USGI Garand barrels are not chrome lined).
Ref:
GCA Journal, Volume 21,Issue 3 Summer 2007
GCA journal again in Fall 2010
Testing a barrel at 50 yards does not mean it will perform the same way at 100 and beyond, the article even mentions this. Ask anyone who shots a lot of long range. A shot out barrel may perform just fine close up then falls apart at longer distances.
If you just want a 50 yard smoothbore musket then do what you will, its your dime. I expect my barrels to perform from point blank out to 500m consistently thus Ill will continue to do proper maintenance on my barrels.
What do you suggest as proper maintenance?
I would think the closer the "damage" was to the muzzle the more inaccurate it could end up being.
Thanks for responding to the question.
At least for the M1 Garand rifle this is a myth that persists, but has been tested and found to be a false rumor.
The hypothesis that "steel cleaning rods cause barrel wear" was tested by the Garand Collectors Association building a test machine that rubbed a steel cleaning rod down the muzzle end of a M1 Garand barrel. Purposely allowing it to rub up against the sides. The results are that there is no noticeable wear on the muzzle even after thousands and thousands of cleaning cycles.
Firing ammo though the barrel does cause the muzzle to erode (show an increase in muzzle wear measurement). Not the cleaning rod.
(On a Garand they use "muzzle wear" and "throat erosion" gauges to measure barrel life. USGI Garand barrels are not chrome lined).
Ref:
GCA Journal, Volume 21,Issue 3 Summer 2007
GCA journal again in Fall 2010
Thank you, SurplusShooter. This is a an on point (although not necesaarily as to chrome lining) responsive answer to the thread theme. Many of you are going off on the cleaning tangent. Please read post # 8 for the more elaboration on the theme of this thread. Thank you.
vicious_cb
08-01-15, 19:57
I didn't think you would have a believable answer. I guess if you thoroughly clean a barrel after every round it will last forever. I am pretty good at math. If it takes $6,000 to wear out a neglected $200 barrel I am good to go with it. I am done. Find someone else to convince your opinion is founded.
Good job putting words in other people's mouths. If you want to resort to childish hyperbole to prove your point why continue?
Apparently its too hard to make a nuanced point. People read the filthy 14 article and stop cleaning their ARs all together.
Chrome is harder than anything else you use on a gun. You're not going to damage it. Any damage from cleaning will be at the crown and cause slight inaccuracy, but it's difficult to make it that bad IMO.
Over cleaning, under cleaning, either way won't make a huge difference in service life. I don't shoot rifle much right now and clean once a year, or if it gets wet. I used to clean every range trip, then i did the math.
If I make $30/hr, and I spend 10hr over the life of a barrel cleaning it, does that make sense?
I would tend to lean towards the minimal maintenance for the desired results. If the desired results are in range, why do more? That is unless another outside issue factors in.
NOT AN EXPERT, but I thought I read chrome lining was instituted to provide better longevity with automatic fired in military firearms. A benefit is easier cleaning and resistance to corrosion. Chrome is VERY tough stuff with a Rockwell hardness generally over 55 (varies by application), while mil spec barrel steel alloys and stainless are Rockwell < 40 (again varies by application).
That's not a bad explanation in a way to explain to people who wouldn't understand the other details.
SurplusShooter
08-03-15, 18:33
NOT AN EXPERT, but I thought I read chrome lining was instituted to provide better longevity with automatic fired in military firearms.
Maybe for US military arms that is true: we were late to the idea of chrome plating, started with the M14.
But worldwide: the earliest use of chrome barrels was the Japanese Arisaka rifle: it had chrome lined bore and breechface, and that was all back in the bolt-action days.
Maybe for US military arms that is true: we were late to the idea of chrome plating, started with the M14.
But worldwide: the earliest use of chrome barrels was the Japanese Arisaka rifle: it had chrome lined bore and breechface, and that was all back in the bolt-action days.
The combustion temperature of smokeless propellants (around 3000F) is higher than the melting point of steel (2750F), fortunately, the duration is very short, but the affects of repeated blast of such hot gas will wear away the steel.
Chrome lining does two things:
1) produces a hard surface that resist the wear of the hot gas on the barrel, and
2) provides an insulation layer that keeps the combustion flame off the steel. Chromium has a melting point about 25% higher than steel and higher than current propellants.
The primary reason this is done is it prolongs the life of the barrel, even at relatively low rates of fire.
A chrome lined bore will make a barrel made from marginal steel last as long as a barrel of good steel. This is the reason it was first adopted by the Japanese, they could get chromium, they could not get either molybdenum or manganese and had to make poor barrels last longer.
Oh, and there other things left in the bore besides combustion products....
I would think that cleaning reduces barrel life.
There is no logic in thinking that removing the copper/carbon fouling to expose bare metal to the bullet's passage would INCREASE bore life over leaving the copper/carbon coating over it.
Copper fouling is as ruinous to barrels as powder gas, and works a lot quicker. Plenty are wrecked by copper deposits. I believe that between pure copper and gilding metal, pure copper fouls worse, as it's soft and tends to smear. It kills accuracy rather quickly as it builds up. In addition to interfering with accuracy, this fouling will not only accelerates bore wear, but also serves as a magnet for moisture. For this reason alone, the investment of a little effort and expense will pay dividends in maintaining your stuff.
From one of the Premier bullet makers, Sierra:
Metal Fouling
Metal fouling may refer to either lead or copper buildup within the bore. This fouling is the result of the friction, pressure and high temperatures inherent in firing. Guns will vary a great deal in their tendency to foul, depending on such factors as the smoothness of the bore, the fit between the bullet and bore, jacket hardness and intensity of the load.
Copper fouling is normally seen as a copper “wash,” sometimes plainly visible on the surface of the bore. Despite its rather innocuous appearance, this fouling can seriously degrade a barrel’s accuracy potential. While removing this fouling can be tedious, it must be done to maintain top accuracy.
Fortunately, today’s shooters have perhaps the best assortment of truly effective copper solvents ever available.
link (http://www.exteriorballistics.com/reference/rifleinout.cfm)
Can you ruin a barrels accuracy by improper cleaning? Yes.
Is it better to just not clean it? No.
Don't be lazy, just learn now you clean it properly. It's really not that hard.
As to the OP question " How Tough is Chrome Lining?" Chrome plating is very hard, but it is thin. It will increase barrel life even if you don't shoot full auto, but it can be damaged by neglect or abuse.
Wouldn't the combustion keep copper fouling to a min based on melting temp?
So what exactly do you mean "damage"? I get that too much copper can degrade accuracy, but can you explain how it causes damage to a chrome bore?
Copper fouling usually occurs forward of the throat, where the gas temperature is much cooler.
As I stated above, chrome is tough, but it is not impervious to damage, the coating thickness in the bore is as thin as .0004" (four ten-thousandths of an inch). Almost all damage to bores, both chrome plated and plain steel is reversible through cleaning.
texasgunhand
08-05-15, 22:30
Copper fouling is as ruinous to barrels as powder gas, and works a lot quicker. Plenty are wrecked by copper deposits. I believe that between pure copper and gilding metal, pure copper fouls worse, as it's soft and tends to smear. It kills accuracy rather quickly as it builds up. In addition to interfering with accuracy, this fouling will not only accelerates bore wear, but also serves as a magnet for moisture. For this reason alone, the investment of a little effort and expense will pay dividends in maintaining your stuff.
From one of the Premier bullet makers, Sierra:
link (http://www.exteriorballistics.com/reference/rifleinout.cfm)
Can you ruin a barrels accuracy by improper cleaning? Yes.
Is it better to just not clean it? No.
Don't be lazy, just learn now you clean it properly. It's really not that hard.
As to the OP question " How Tough is Chrome Lining?" Chrome plating is very hard, but it is thin. It will increase barrel life even if you don't shoot full auto, but it can be damaged by neglect or abuse.
This... I agree, cleaning properly is the key. I only use coated rods anymore. There are just ton of articles at accurate shooter and tibosuresrex on you tube that explains what cleaning to much does.
I clean and lube a gun after I shoot it. I have 60 year old rifles that shoot just fine and have been cleaned everytime they have been shot when they get home. Chrome lined bores are tough and are made to help a not o great barrel also to help keep them from rusting in wet environments like damp jungles etc. I clean mine and run an oily patch through the bore before they go back in the safe. But thats just me.
ZipZopBoop
08-06-15, 08:32
Copper fouling usually occurs forward of the throat, where the gas temperature is much cooler.
As I stated above, chrome is tough, but it is not impervious to damage, the coating thickness in the bore is as thin as .0004" (four ten-thousandths of an inch). Almost all damage to bores, both chrome plated and plain steel is reversible through cleaning.
Reversible or preventable? I assume you just made a careless error but I don't have enough knowledge on the matter to say for sure :p
Reversible or preventable? I assume you just made a careless error but I don't have enough knowledge on the matter to say for sure :p
dam·age /ˈdamij/noun - 1. physical harm caused to something in such a way as to impair its value, usefulness, or normal function.
A barrel that is fouled by copper and unable to achieve the accuracy that is had when it was new is "damaged". A good cleaning and removal of the copper fouling will restore the barrel to its original accuracy level (minus expected drop off due to throat and muzzle wear), therefore the damage is reversible.
And yes, it is also preventable, by just cleaning it properly.
Ming_the_Merciless
08-06-15, 14:41
I have read that chrome lining is extremely tough and that is why bores and chambers are chrome lined. It is supposed to significantly increase barrel life. On the other hand, you hear warnings to not be overly aggressive with cleaning rods as you can damage the chrome lining on a chamber and/or bore.I just wonder, when common sense kicks in, how can a steel cleaning rod cause damage to the chrome lining when steel cased ammo continually rubs the chamber, and metal clad bullets are going down the barrel at great velocity.
A material's resistance to localized plastic deformations, small dent or scratches, is characterized by hardness.
The hard chrome plating in bores, hydraulic cylinder rods, rollers, piston rings, etc., is different from the decorative chrome on your car bumper that requires an underlying nickel and/or copper plating for the chromium to adhere to. Hard chrome plating is applied directly on the substrate a couple thousandths thick, providing improved hardness than otherwise present, typically resulting in a Rockwell Hardness (C) of 60-70. For reference, ballistic rated steel plates are around 50 on the Rockwell C scale or 500 on Brinell hardness scale. This harden surface on top of the substrate improves durability offering higher abrasion/erosion tolerance and oxidation resistance.
Cleaning rods are made of softer alloys like aluminum, brass, or mild steel. These alloys cannot be rated using the Rockwell C tests due to their inherent softness, but can be rated on a different scale, about 50-100 Brinell hardness.
Thus a typical cleaning rod yields first and won't damage the bore of a chrome-lined rifle. Though for the price, and piece of mind I still use a nylon coated cleaning rod for chrome-lined rifles the same that I use for my precision rifles.
Also, if chrome lining on a chamber is damaged (scratched), what would be the effect?
Also, if chrome lining on bore is damaged (scratched), what would be the effect?
Any imperfection, pitting, chatter marks, results in high stress concentrations, which under abrasion and thermal fatigue initiate crack nucleation. The micro and macro cracks provide a path of least resistance for the hot gases to erode the substrate. However, if the substrate was also case hardened, nitrided, this would further increase service life. I don't believe any small arms manufacturer currently employ this technique, though it's been or has been suggested on large caliber weapons system to help reduce replacement costs.
A prime example of micro and macro cracking is shown in cut away views of gas port erosion in chrome lined barrels.
http://i48.tinypic.com/11wg21i.jpg
A barrel that is fouled by copper and unable to achieve the accuracy that is had when it was new is "damaged". A good cleaning and removal of the copper fouling will restore the barrel to its original accuracy level (minus expected drop off due to throat and muzzle wear), therefore the damage is reversible.
And yes, it is also preventable, by just cleaning it properly.
I know Todd Hodnett from Accuracy 1st, and two instructors I had last year, former Army sniper, Adam Whitecotton, and former Marine Scout sniper, Joshua Stabler, and number of other precision rifle shooters I've met are in the school of thought to not bother with the copper fouling, unless it's excessive, and you notice a degradation in accuracy. This supposedly helps to reduce clean and cold bore shifts, and lessen extreme spread in MV - as you have to re-foul the barrel to retain precision. Though I also know some shooters who still strip their bores completely, but they record their shift in a data book and know exactly what that is if any is present.
So I've followed up on their suggestion and stopped stripping the copper out, and instead focus just on the carbon. Thus far I've haven't observed any noteworthy loss in precision, I've got one precision rifle, approaching nearly 1k rounds (don't have my data book with me), 7.62 OBR and hasn't had the bore cleaned with copper solvents, as much as the "white-glove" clean OCD in me, wants to strip the copper all out, I'll keep going until I notice my group size increase.
I also had a chance to demo a articulating borescope and inspect my rifles a few years ago prior switching to carbon removal method only. Of course to conduct a proper inspection, I thoroughly cleaned the bores. Or so I thought - I was surprised, even with routine cleaning regime of mild copper solvents, Hoppes #9 over the years, and followed by occasional heaver solvents like those foam bore cleaners, the copper galling was still present. The copper galling filled in the chatter marks in the barrel, like the one shown below. Match/stainless barrels have chatter marks, some less than others, but with chrome-lined bores, the incipient micro cracks inherent to the plating process and also the amplification of imperfections makes for quite a dramatic difference under a bore scope. It seems to copper foul more, but I had a limited sample size with my impromptu time with the bore scope. The copper galling was however most prominent an inch or so forward of throat and also aggressive around the gas port area.
http://www.armoryblog.com/wp-content/uploads/2013/09/6.5x47-lapua-chamber-cutaway.jpg
Match/stainless barrels have chatter marks, some less than others, but with chrome-lined bores, the incipient micro cracks inherent to the plating process and also the amplification of imperfections makes for quite a dramatic difference under a bore scope. It seems to copper foul more, but I had a limited sample size with my impromptu time with the bore scope. The copper galling was however most prominent an inch or so forward of throat and also aggressive around the gas port area.
http://www.armoryblog.com/wp-content/uploads/2013/09/6.5x47-lapua-chamber-cutaway.jpg
Caused by the forcing cone effect. The bullet will make a free-bore jump with gas blow-by until it hits the new "leade" edge and starts to engrave into the lands. Chrome will strip from the throat and the tops of the lands from both abrasion of the gilding metal jackets and heat/gas corrosion.
I don't know if anyone does both nitriding and chrome-plating as well (which would raise the cost per individual barrel).
Ming, thank you for your excellent response to my questions that you quoted.
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