Barrel: stainless, chrome moly, etc.

[BigDave]

For someone who is starting out with an AR, and would use it for 3-gun, and the occasional dispatch of a coyote, which is the the better option?  I've heard all kinds of stories.  Chrome-lined wears better, but accuracy is not as good as stainless, etc, etc, etc.

[Patrick Sweeney]

The NRA High Power shooters eschew the use of chrome-lined barrels, but they are the only ones so picky.  I've easily dumped the 300 M pop-ups on a NG range with an iron-sghted shorty with a chrome-lined barrel.

That said, I'd get a stainless.  The only reason is that the chamber and leade can be reamed to adjust headspace in the event your new barrel ends up at or under minimum.

Twist: 1/9.  Slower precludes the use of heavy bullets, faster, you don't really need.

[kellyn]

Chrome-lined barrels tend to be less accurate because the chrome is not evenly applied throughout the barrel.  I doubt you'll ever see a chrome-lined barrel in the winner's circle at Camp Perry, more likely a Kreiger stainless.

That being said, chrome-lined barrels last a long time and some or even most may are up to the accuracy standards of 3 gunning.  3 gunners do not need a 1/2 MOA gun to win. (highpower shooters probably don't either!)

In the end, I agree with Patrick.  If I were getting a new barrel I would get a stainless 1 in 9 twist.  We may not need the extra accuracy but I sure like it!

[Carlos]

Agree - and note most makers give you a choice except Bushmaster. Their enhanced accuracy models (ie heavy and bull barrels) likely have as much accuracy as you "need" for 3 gun, but unless a smokin deal comea along on a BM, go for the stainless 1/9 or 1/8 in 18 to 20".

[gary meyer]

whats better for a sniper rifle?

[cking]

Most are using stainless, what more important is who makes the blank and then who cuts the chamber. Compass Lake engineer is one of best, and fast.

[dghboy315]

what are the basic differences btnw a stainless steel barrel and a chrome lined barrel? which would be better for a 3 gun rifle?

[kellyn]

Get a SS barrel. Chrome lined barrels have a layer of chrome applied over the rifling, which is ok to protect the rifling but it sure does not help accuracy since the chrome will never really be evenly applied. This is not to say a chrome lined barrel can't shoot well, it is just less likely to do so. 3 gun matches aren't (yet) held in the jungles of the Amazon so don't feel the need for a chrome lined barrel.

[George]

Kurtm has another thread going here where he points out that chrome lined barrels are fine for 3-gun and may just offer the benefit of extended accuracy life over SS.

My take on this (read theory) is that throat erosion is the real culprit in accuracy falloff and that a SS barrel where the throat is dressed using lapping rounds ocassionally (Tubb FinalFinish System) will have just as long a service life as a chrome lined bore and be more accurate to boot.

My JP 1:8 20" stainless is at just about 10k and it still holds almost the same as it did when it was low mileage (under .5 MOA new, about .6 MOA now). I run 3-4 Tubb FF bullets through it every 500 rounds and that seems to be doing the trick. Of course, I don't have an identical one to not use FF rounds in it and run a comparison.

Anyone out there with info on how their JP SS bbl is lasting without lapping round maintenance?

--

Regards,

[Zak Smith]

The FN SPR and Sako TRG-42 rifles have chrome lined barrels and they shoot good.

Some elsewhere have suggested that most CL AR15 barrels aren't as accurate as they could be because they don't start with match quality blanks nor take extra pains to ensure consistent lining. I don't have any data about it, though.

-z

[Wap wap]

Chrome lined barrels aren't really chrome lined -its a vapor deposition. Orginally it was instituted to stop the corrosion not erosion of primers salts that were compounded using potassium salts, that when deposited on the barrel would hygroscopically absorb moisture from the air and corrode the barrel with the action much like a car fender during the winter. The major difference (certainly not power factor) is the leade difference in the throat- Chrome lined barrels tend to come from manufac. that do military contracts thus have NATO throats which are longer and allow for pressure increases when the gun is fired rapidly (read full auto) caused by expansion in the metal local to the throat area. SS 416 barrels are cut to SAAMI specs. which have shorter leads and the bullet contacts the rifling earlier thus better accuracy. Military barrels have all kinds of roll stamps MP (metal particicle-fluxing) etc. to prove that some piece of sh*t was not slipped into the system for profit. High quality broach cut 416 barrels have already admitted profit and compete in the market place. (read pretty hard to get a bad barrel). As far as accuracy, I would truely like to see a military barrel compete with a good 416 with handloads before As to wear, I have measured 416 barrels with 20,000 rounds with erosion gauges that still shoot better than new chrome lined barrels. The chrome lining will still wear at the leades and erode, In short barrel life is not an issue with either, but reliability is, and can only be assessed on an individual gun basis.

[anttiman]

I am going to purchase my first AR this year. I have been trying to decide whether I should buy rifle with chrome lined barrel or not. My number one priority is the reliability and accuracy comes in second. I would be satisfied to 1-2" MOA accuracy @ 300 meters. I am probably getting the 5.56 NATO chamber even if it would mean loss in accuracy. I want a rifle that´s able to shoot all kinds of ammunition from Wolf to military surplus. I am going to use my rifle in IPSC and 3gun-type military shooting all-year-round in sometimes harsh climate of Finland.

Is there significant reliability difference with chrome lined chambers and chambers without it?

I have understood that chrome lined chamber is easier to clean and that it helps the case extraction by reducing the friction between chamber wall and the case. Moisture and powder residues builds up quicker to chambers without chrome lining. Are there truth in these claims?

-Antti

[Wap wap]

In semi auto and full auto weapons the brass case acts as a radiator to extract heat from the walls of the chamber(why the hot when one lands on your neck). The particular cycle rate of the weapon and the amount of powder burned determine the initial temp of the chamber, obviously 50's are hotter than 30's etc. The powder forms varnishes and lacquers as it burns and coats the linings of the barrel. Military bullets have more copper in them and little Zinc to act as a gilding metal, which decreases the coefficient of friction, and thus copper wash on the lands. I have had more problems with badly head spaced chrome lined than stainless. ---but--- these were cheap barrels. Target grade stainless tend to be more expensive--less--- deviations from tolerances. With the use you describe the chrome lined would be a good place to start. Using a military chamber brush will solve the problem in either case.

[Esa1195]

Is it possible to cut hard chrome lined barrel shorter without ruining accuracy? Will it chip?

[SRT Driver]

I put a Bushmaster Chrome lined BBl on a Nat'l Match upper (float tube, good sights, etc) a couple years ago to try out this very issue.

I used it out to 300 yrds (the Natl Match short course) with 68gr Hornady bullets. 1-9 twist. 52's worked well too.

The result - More accurate - no, less accurate - not really. It held x-ring.

Did it matter - no, I just cleaned the bore a whole lot less.

Did it last - yes, it still shoots fine.

Will I shoot it at 600 - No. 80's don't spin in a 1-9 twist.

[Wap wap]

The chrome isn't really a lining as such, it is a thin layer of vapor not much thicker than bad copper wash from shooting to much and not cleaning, i forgot the thickness, but it would surprize how thin it really is. It does not chip and shorting works great, just remember that the barrel should not be cut back to the sight, gas tube or the pressure reserve impulse curve will not operate the bolt. Touch up the crown with something like an RCBS case bevel or large drill bit, hand turned.

[RAZZ]

I am planning on picking up a RRA AR in the not too distant future, and I was wondering if any of you had any thoughts as to which barrel to go with...Standard chrome molly, chrome lined or stainless. The $ aspect isn't a big deal, I think its only $50 or so difference for the "upgrade", just wondering if there is a best chioce for general 3-gun use. Thanks.

[benny hill]

Stainless.

[Bear1142]

As always, Benny is a man of very few, but very important words.

Erik

[wsimpso1]

Chrome lining of the bore and chamber was put on military barrels to prevent corrosion from tough field conditions and to allow use of corrosive (chlorate type) priming. The US and western European militaries have been using non-corrosive priming since the 1950's, but many other countries were still producing perchlorate type primers until recently. Take Away - Civilians really do not have much need for Chrome Lining.

Chrome lining can be applied to any barrel, good or bad. If it is applied to an excellent barrel, it can be great. I have one (an older 7" twist Colt) that was not quite up to standards, and I put the 3-4-5 bullets of the Tubb FF kit through it and now it shoots match bullets under a minute. I have another that saw the same treatment and it is maybe a 2 minute barrel. Now, since these chrome barrels are usually made to military standards (accuracy requirements are looser than for civilian arms), which end of the quality spectrum do you expect a chrome lined barrel will usually fall into? Take Away - You can get an excellent chrome lined barrel, but that you should not expect it...

High Power Experience - Barrels made of chrome-moly steel or stainless steel from the same maker will be on par with each other for accuracy when new and early in their lives. If well cared for (One piece coated rods, brass jags, rod guides, copper solvent, JB or Rem Clean, avoid damaging the throat and crown, and maybe Tubb TMS bullets) both will give good life but the stainless ones will age more gracefully and give excellent accuracy for longer. If your cleaning technique is sloppy or you use jointed rods, the stainless barrel will get damaged more easily, but nothing, not even chrome lined, will hold accuracy under that abuse. The stainless barrel will resist a humid environment better. Take Away - Stainless serves us better if we are careful with our barrels. Chrome moly will stand abusive cleaning a little better. Chrome lined will stand abusive cleaning only a little longer than chrome-moly.

The folks that build high quality barrels (there are several excellent barrel makers, and they sell their blanks to people noted for doing an excellent job of turning out barrels) stand behind every barrel they make. These folks do not build chrome lined barrels. Your odds of getting excellent barrel are much better with these folks.

Overall, I like Benny's answer, but felt that if the reasons were listed, it might help you...

Billski

[RAZZ]

Thank you all.