Rifle barrel accuracy and longevity - Carbon steel or stainless steel?


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AirPower
May 2, 2008, 09:05 PM
I'm thinking of getting a bolt action, either carbon steel or stainless steel versions are available. SS is probably easier to maintain but I wonder if carbon steel barrel lasts longer and stays more accurate over time compared to stainless?

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Onmilo
May 2, 2008, 09:13 PM
In my personal experience, there is no appreciable longevity advantage of carbon steel over stainless steel.
A really well made carbon steel barrel will usually display a slight advantage in accuracy over a really well made stainless steel barrel, but the advantage is so slight that only the most serious target shooter may notice it.

HM2PAC
May 2, 2008, 09:18 PM
I have been told by numerous people that SS is more difficult to work with. When my barrels are being made, I want the smith to have to sweat it the least.

Swampy
May 3, 2008, 08:16 AM
Longevity and round count life is something I cannot comment on..... but as far as whether or not Stainless may be more accurate than chrome-moly, all you have to do is go to any "Accuracy Event".

Walk the firing line at any benchrest match (Short range or Long Range) and you will look in vain for any evidence of a chrome-moly tube. EVERYBODY shoots stainless. Same thing at any F-Class, Palma, or Match Rifle Highpower event.

I think this pretty much tells the tale on which type is the more accurate barrel metal.... don't you?? ;)

Best regards,
Swampy

Garands forever
2007 NRA Missouri State 600 yard Service Rifle Champion.... with an M1

frank green
May 3, 2008, 11:07 AM
Guys, If I had to pick one I would lean towards the c.m. lasting longer but keep in mind that there are so many variables in shooting it is hard to put an exact number on it. One is powders. Some powders do wear the barrel faster.This is not just an opinion but data that we have on how long ammunition test barrels are lasting etc...

I see no accuracy difference between c.m. and s.s.

The s.s. actually machines a little easier than c.m.

Also keep in mind not every barrel maker is using good quality steel. The crappier the steel the hard it can be to work with weather it is c.m. or s.s. I know there are a few barrel makers here in the states that are using s.s. being made over seas and are having a real problem with it in how it machines.

Why do you see more s.s. barrels on match guns. One reason is you don't have to put a finish on it to help protect it from rusting. The s.s. is more forgiving than the c.m. but don't forget the s.s. can still corrode. It doesn't get that reddish rust color to it but it will corrode still if neglected etc...Also sometimes the s.s. will break in a little faster but in the real world I don't see a difference in accuracy between the two metals.

I have two barrels on my match rifles that are c.m. one is a M14 and the other a bolt gun for F-Class and tactical matches. Both shoot as good as any s.s. barrel I have on my other guns.

Later, Frank
Bartlein Barrels

AirPower
May 3, 2008, 01:30 PM
Great info, thanks guys. I was trying to exclude one from the other other, and it looks like the metal may not be an issue. I also think that people tend to go to SS because they dont' have to spend as much time caring for it, so you can spend more time shooting.

Now, something a twister, I've seen chromelined carbon steel barrel, but never a chromelined ss barrel. Is that because chrome is only there to prevent corrosion in the barrel? What about chrome's lubricity that people talk about that aids the bullet?

Vern Humphrey
May 3, 2008, 02:41 PM
You won't shoot out your barrel in your lifetime -- nor will your son and grandson. Pick what you want, and don't worry about longevity.

Walkalong
May 3, 2008, 02:56 PM
For normal shooting, Vern is right as usual. You would need to shoot a lot to shoot out a good barrel.

SimpleIsGood229
May 3, 2008, 03:01 PM
As far as machinability, I think it really depends on which specific alloys are being dealt with. I'm not thinking that stainless vs. non-stainless has much to do with it. I could be wrong, though.

Originally posted by AirPower:
Now, something a twister, I've seen chromelined carbon steel barrel, but never a chromelined ss barrel.
My guess is because chrome lining is a military thing (generally), and the military (generally) doesn't use stainless.

Is that because chrome is only there to prevent corrosion in the barrel?The military uses chrome lining for longevity, as I understand it.

What about chrome's lubricity that people talk about that aids the bullet? That comes into play, mainly, for ease of extraction (military rifle, dirty chamber, bad conditions, etc.).

Also, I know from experience that a chrome-lined barrel is one heckuva lot easier to clean.

SlamFire1
May 3, 2008, 11:15 PM
Now, something a twister, I've seen chromelined carbon steel barrel, but never a chromelined ss barrel. Is that because chrome is only there to prevent corrosion in the barrel? What about chrome's lubricity that people talk about that aids the bullet?


Military barrels have been chromed because the military is interested in long life. A chromed 308 barrel will easily give 10000 round barrel life, a non plated barrel will give about 5000 rounds. The chromed barrel is more resistant to rust, and a chromed chamber is better for semiautomatic weapons because it is slicker. That reduces breech friction, and breech friction is undesirable. Life would be so much easier if frictionless cases existed, all you would have to do is open the bolt and the cartridge would fall out. Instead, we have brass, or worse, steel cases, that stick to the chamber walls and have to be yanked out. Sometimes they don’t come out at all.

If you look at AMCP 706-252 "Gun Tubes", there are explanations for the materials used in barrels. This publication was published in 1964, and the in American inventory rifle designs then, have not changed much, nor the materials. I do not know why the military today does not use SS, possible because carbon steel costs less and they are familiar with it.

I don't know if you could chrome line a SS barrel. I don't know how anyone chromes SS anyway. Stainless forms an oxide on the surface, I thought that prevented chroming. Anyway, getting a uniform layer of chrome down any barrel is a trick.

Looking at page 68 in AMCP 706-252, 4150 is listed as a small arms barrel material, and that is probably what was used in the M14. This material was used in the Garand for a barrel material. Also listed is a material simply called Cr-Mo-V. Which may be why carbon steels barrels are often called “Chrome Moly”. I was unable to find an exact equivalent on Mat Web. Cr-Mo-V has Mn, Cr, Mo and Vanadium. I notice ER Shaw is using 4140 as a barrel material.

I hate to bust anyone’s bubble, but barrel material does not mean much towards accuracy, or barrel life. My first year at Camp Perry, I remember talking to the USMC rifle Team Armorer’s about barrels and barrel materials. They are often given barrels, and often, they buy barrels. They have no brand or material loyalty. They had on the line barrels by everyone. What counted was that the barrel shot within their spec’s. Which then was three inches at 300 yards.

I have confirmed this non difference when talking to many competitors. Highpower rifle guys usually keep careful count of the rounds through their barrels, and there is no correlation between material and barrel life, or accuracy. Stainless is very popular, perhaps most popular, because it won’t rust, and who cares if you scratch the thing. After you add in the cost of bluing a Chrome Moly barrel, you are just at the price of a Stainless blank. And the first scratch, well, it is a horrible eventuality. (An ER Shaw SS is $220.00 , a 4140 barrel is $150.00 and the bluing is $100.00)

Personally I prefer on my service rifles, Douglas chrome moly barrels. I get them parkerized, they look military, and they are easy to take care of. And they are at least $75.00 to $100.00 less than a stainless barrel. http://www.benchrest.com/douglas/price_list.html Most factory NM AR rifles come with SS Wilson barrels, that is what the market wants, and that is what comes on the rifle. My Bushmaster NM AR has chrome moly barrel. Shoots just as good as my SS Rock Island NM AR. And, I suspect they are both Wilson barrels.

My Space gun has a Stainless barrel. A carbon steel Krieger was not offered in the configuration I wanted.

Conqueror
May 3, 2008, 11:44 PM
For normal shooting, Vern is right as usual. You would need to shoot a lot to shoot out a good barrel.

Considering the OP didn't mention the caliber or type of shooting, that's a pretty silly statement IMO. Plenty of benchrest shooters go through a barrel a season, or a barrel every other season. A thousand rounds of hot ammo can cook a barrel pretty well.

gunnie
May 4, 2008, 08:54 AM
Conqueror,

easy there...he did say, "for normal shooting". i'd have to agree competetors shoot more in one season than joe average does in one life.

gunnie

Ash
May 4, 2008, 09:10 AM
And a competition barrel would never, ever, be judged shot out when it comes to regular shooting. A barrel deemed no longer suitable for competition would work just fine for informal paper-punching as well as be perfectly accurate for hunting. I wager that there are a great many commercial hunting rifles that have barrels that are less accurate than a "shot out" competition barrel.

Ash

P-32
May 4, 2008, 09:39 AM
Hey Slam Fire, you should try out a Kreiger one of these days........Mines easy to clean, makes no copper and shoots great.

I will agree with the Douglas barrel thing. Douglas is hard to beat when they are shooting for the money.

SlamFire1
May 4, 2008, 12:17 PM
And a competition barrel would never, ever, be judged shot out when it comes to regular shooting. A barrel deemed no longer suitable for competition would work just fine for informal paper-punching as well as be perfectly accurate for hunting.

Absolutely true. Competition barrels have to perform all the way back. I have heard it said, and I believe, that 600 yards is a test of the man, barrel, and his load.

When my first M1a barrel was on its last legs (har, har) and had about 5000 rounds through it, it would barely hold the 10 ring at 600 yards. However just before I replaced it, I got to shoot in a 300 yard reduced match. I shot a 195-12X on the three hundred reduced target, and that target is a difficult target. The X ring is 2.85" and the ten ring is 5.85". Out to 300 yards a worn out competition barrel will still shoot quite well.

USSR
May 4, 2008, 03:05 PM
Walk the firing line at any benchrest match (Short range or Long Range) and you will look in vain for any evidence of a chrome-moly tube. EVERYBODY shoots stainless. Same thing at any F-Class, Palma, or Match Rifle Highpower event.

+1.

Don

Ridgerunner665
May 4, 2008, 03:12 PM
Stainless steel resists throat erosion better than chromoly steel.
Stainless is also more accurate IF its properly lapped.

Grndpndr
May 4, 2008, 09:44 PM
Ive heard the opposite concerning CC and CM ad CM supposedly lasting longer but its moot to me anyway.If ishoot 5000-7000 rounds at todays preices Ican buy lots of match bbls.Far as a Mia s a targe type or even DM unless your the mitary with nlimied funds stick wih a bolt gun specfically the SAVAGE.I bought a STD M1a NIB and ve hd nothing but trouble with it.Though SAI did fix all the mechanical faults whichmounted to 3-4 trips to replace the reciever ,try to iindex the bbl reciever properly king it worse ad unsafe to fire, returned it again where he custom shp refaced ny new reciever n\d fitted a new bbl which tok care of the mechanical warranty part but the fruberglass g stick w/GI M trigger groupI purchased hs NO forend pressure which as all M1 people know destrys accuracy calling for a bedding job and another 200 +$
from any G-smith.Mine sa8d he wouldnt bed a GI fber sock anyway but would sell me an unclaimed laminated wenigs stock for anoter $275 finished the total amounting to some $475.Plus all the USGI pars in exc + to new cond i have at least $2000 in a std as it sits and it wont shoot into 3.5MOA at 100m w 168gr fed match.While my HBAR shoot rings around it with 62 gr ball.Bout ready to sell it and the GI parts for a PTR/savage that needs no $$ accurizing let alone a $250scope mount that may or may not fit less another $45 fee to fit to reciever plus ringsthat needs no acurizing and in fact the PTR has no acurizing manual aside from a beter bbl. My opinion M!1As are a hobby gun for me with DEEP pockets.

frank green
May 5, 2008, 08:57 AM
Airpower, For the most part the chrome lining was/is there to help prevent corrosion. Remember back when the military was using corrosive ammo. The lubricity thing. That's a new one! I think I've heard that before but I have never seen anything anywhere in terms of documentation or talking to ordnance personal in the military that ever said anything to that effect.

You don't want a chrome plated bore from an accuracy stand point (match guns not military guns is my point of view here) because as you shoot a chrome plated bore the chrome plating when the throat starts to crack and wear chunks of the plating will start to flake/break out and as this happens it will/scratch the bore really bad. The chrome plating is very hard and when you have a small pieces laying in the barrel from when it is wearing and you are shooting one round after another down it each bullet being shot the plating particles gets caught between the bullet and bore and dragged down the barrel.

Also when the bore is chrome plated usually/sometimes the plating can build up a little heavier at the ends of the barrel. Chamber and muzzle. From an accuracy point of view this is not a good thing. Now you have a bore uniformity problem and if the bore is tighter at the breech end and gets bigger towards the muzzle end your accuracy suffers. Keep in mind that a gun being built for competitive shooting vs. a combat gun are two different things. What the military needs/specs. for accuracy is completely different.

Simpleisgood229, The chrome plating does nothing for barrel life. I have test data and also have talked to people at places like Lake City Army Ammunition plant etc....A chrome lined barrel doesn't last any longer than a non chorme lined barrel. Even test data that I have on British machine gun barrels they showed no real increase in barrel life one over the other. They showed a Vickers and Bren machine gun barrels had an average life of 12,000 - 15,000 rounds (machine gun accuracy but the barrel would still function even after the accuracy dropped off. The barrel could still be used but it was not recommended for what is called overhead fire) and a chrome lined barrels in testing only went approx. the same amount.

Also most of the test barrels we make are made out of c.m. approx. 98% vs. s.s. A lot of the testing companies weather they make complete ammo or components have told me that they see the c.m. lasting longer over s.s.

Slamfire1, I would agree with everything you said but add that the reason s.s. is not used by the military is because as the temperature drops (I don't know the exact temperature number lets say it is 0 degrees) the s.s. becomes more brittle/less impact resistance. We are making some barrels right now and the end use is most likely going to be the military (I know who but can't say and I also can't say who is building the rifles etc...we have to abide by a non-disclosure agreement) and c.m. was spec'd because as I was told the operating temperature of the rifles in a combat environment will be down to -60 degrees F. Now as we all know the average hunter, match shooter etc....will not be shooting in conditions like this.

Ridgerunner, Yes the c.m. and s.s. do wear differently especially in the throat but I don't see a difference for the most part in barrel life and it is not true about the lapping and s.s. being more accurate.

Yes you can get a less expensive $$$$ barrel and it shoot really well. One thing that you all should know is that the cut barrels on average last longer than a button rifled barrels. This is because the button rifling work hardens the bore. Remember the old saying you get what you pay for.

Also the from one barrel to the next the cheaper the cost usually the more variances in the barrel blank and this can effect how it shoots. From accuracy, to barrel life, how it cleans etc....

Guys keep in mind there are a boat load of variables in shooting and guns. One example is that some powders are harder on barrels than others and that alone will reduce barrel life is one and how it is cleaned and taken care of and also how it is shot. Do you get the barrel really hot like a prairie dog shooter, F-class shooter, high power shooter vs. a hunter who takes his gun out twice a year and also what the gun is chambered in. A guy shooting a .223 chambered gun vs. a guy shooting a .220 swift. When ever you increase case capacity or reduce your bore size you will shorten barrel life also.

Later All!
Frank @ Bartlein Barrels

AirPower
May 5, 2008, 12:25 PM
Thanks Frank, that's a great summary on the barrel info, very informative.

Could you elaborate on the "cut barrel" vs. button rifled barrel? Which one is what they call "cold forged" barrel? It seems that European gun makers (such as Sig or Steyr) consistently talk up about their superior cold forged barrels. Does that affect barrel accuracy, or does it simply make the barrel last longer?

USSR
May 5, 2008, 01:38 PM
Could you elaborate on the "cut barrel" vs. button rifled barrel? Which one is what they call "cold forged" barrel? It seems that European gun makers (such as Sig or Steyr) consistently talk up about their superior cold forged barrels. Does that affect barrel accuracy, or does it simply make the barrel last longer?

AP,

Not Frank, but. Cold forged barrels, or better known as hammer forged barrels, are an entirely different creature. Whereas cut rifled and button rifled barrels begin with barrel bar stock in which a hole is drilled in it from one end to the other, hammer forged barrels start from a short, fat piece of steel which is put in a hammer forging machine which "pounds" the barrel on all sides, causing it to lengthen and assume the contour that the forging machine is set to produce. Hammer forged barrels are common for most factory produced hunting rifles, but are not known for match accuracy, and you are not likely to see them in competitive circles.

Don

Onmilo
May 5, 2008, 08:57 PM
I would beg to differ in that the majority of commercial rifle barrels, at least in the USA, are button rifled chrome moly steel.
The Russians used hammer forged Match grade barrels on their Competition rifles for years and may still do so.
Diemaco or Colt Canada, or whatever they are calling themselves this week, use hammer forged barrels on the production of M16 type rifles with very good results as to longevity and accuracy standards.
Diemaco barrels consistently exceed minimum accuracy standards and barrel life expectations.

Match shooters will claim that a button rifled barrel will outshoot a broach cut barrel when new, which is true.
A broach cut barrel will outshoot a button rifled barrel once settled in, and continue to do so for a greater number of rounds, I absolutely agree with this assessment.
Hand lapping and cyrogenic stress relief will make a broach cut barrel that is generally superior to a button or hammer forge rifled barrel in every way if done correctly.

SlamFire1
May 5, 2008, 09:11 PM
Simpleisgood229, The chrome plating does nothing for barrel life. I have test data and also have talked to people at places like Lake City Army Ammunition plant etc....

I only have estimates of chrome barrel life from people who opinions I respect. If you have real barrel life data, especially for the .223, please post it.

I have friends who work on the rebuild lines for M16's/M4's. They tell me that they gage barrels, assemble the rifles, and lot sample completed rifles with 6000 round tests. Basically the rifle is shot as fast as can be, compressed air being blown through the barrel as the next magazine is put in the mag well. I was told that it was likely that some of the barrels had been on a couple of rifles before being put on a rifle for the 6000 round test, and the chrome lined barrel still gages good afterward. That is a pretty good barrel life.

And, almost no rifles fail the 6000 round test with a broken part, which speaks well of the endurance of the M16 design.

Asking around, the average .223 Match barrel lasts less than 10,000 rounds, a lot fail around 7000 rounds.

Hammer forged barrels are common for most factory produced hunting rifles, but are not known for match accuracy, and you are not likely to see them in competitive circles

I don't think I have ever seen one. I really wonder if the stresses caused by hammer forging would cause the barrel to walk, as it heated up.

However there might be a contributing factor. Most premium barrel makers are small shops. I have heard prices for hammer forging machines that were very high. Perhaps a million? I don't remember, but it was a God Awful high number, too much for anyone but a Transnational Corporation with a Government contract .

USSR
May 5, 2008, 09:23 PM
As far as I know, only Savage barrels are button rifled. Remington, Winchester, and Ruger factory barrels are all hammer forged.

Don

SlamFire1
May 5, 2008, 11:13 PM
Well, I guess I don't know what a hammer forged barrel looks like, as my Ruger M77 Tactical must have one. No funny marks or nothing. And it shoots just fine.

This was at 100 yards, prone with a sling, with it.

http://img.photobucket.com/albums/v479/SlamFire/Ruger%20M77%20Glassbedded/ReducedRugerM77glassbedded.jpg

bogie
May 6, 2008, 02:16 AM
I think I've seen one, maybe two CM barrels at benchrest matches.

Generally from folks who liked to experiment.

bogie
May 6, 2008, 02:17 AM
Slamfire, sorry about that big group there... You may want to try shooting over windflags to tighten up the horizontal. And it looks like you need maybe a half-click more powder to hit a sweet spot for the vertical.

SlamFire1
May 6, 2008, 10:12 AM
Slamfire, sorry about that big group there... You may want to try shooting over windflags to tighten up the horizontal. And it looks like you need maybe a half-click more powder to hit a sweet spot for the vertical.

Thanks for the sympathy. :D

That was the first group I shot out of that 308 Win rifle after glassbedding the thing. In the factory configuration it was a 1.25-1.5 MOA rifle, but as the action beat against the wood, it got worse.

So after finishing a Club reduced course rifle match, I pulled the Ruger out and fired five rounds. Looked through my spotting scope and decided that I ought to quit while I was ahead.

Can you bronze a target?

The older I get, the better I was. ;)


http://img.photobucket.com/albums/v479/SlamFire/Ruger%20M77%20Glassbedded/96ReducedRugerM77afterGlassbeddingD.jpg

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