Why are chrome lined barrels less accurate?

[TMiller556]

I see everywhere that chrome lined barrels are supposedly less accurate than stainless steel or chrome-moly barrels. Is this true? If so, why? I'm just curious and I've tried searching for the answer and I can't find anything. If anyone can help me out, I'd really appreciate it. Thanks in advance.

 

[Hollerpoint]

My chrome lined Del Ton barrel shoots better than most of the stainless or chrome moly barrels I know of......using handloads. Specs on the handloads are 26.2 grains of IMR 4320 under a 55 grain Hornady soft point using CCI primers. Ive heard chrome lined barrels are supposed to be less accurate but that has not been the case in my experience.

Oh, this is a parts-gun AR-15 that I speak of.... .25MOA and I'll be happy to post targets.

 

[TMiller556]

My chrome lined Del Ton barrel shoots better than most of the stainless or chrome moly barrels I know of......using handloads. Specs on the handloads are 26.2 grains of IMR 4320 under a 55 grain Hornady soft point using CCI primers. Ive heard chrome lined barrels are supposed to be less accurate but that has not been the case in my experience.

Oh, this is a parts-gun AR-15 that I speak of.... .25MOA and I'll be happy to post targets.

Thanks for the reply. I heard that unless you're shooting targets, the difference in accuracy between the barrels is negligible, so that might be the case. I just read that it has something to do with the unevenness of the lining or something.

 

[rcmodel]

I have an old Colt SP1 pencil barrel carbine that is crome lined.
It shoots well under MOA with handloads.

Doesn't seem like it could do any better without chrome lining.

rc

 

[briansmithwins]

For hardchromed barrels they cut the bore oversize and then plate it back to the correct dimension. Chrome can build up unevenly in both cross section and though the bore's length.

That said, modern (as opposed to WWII era) metal plating is pretty good.

BSW

 

[Redlg155]

Uniformity of the plating process has always been a concern. In addition, plating may magnify any serious imperfections or areas of constriction.

All being said, each barrel is unique in itself. A chrome lined barrel may outshoot a conventional barrel at times, other times it may not.

 

[Powerglide]

I concur with Red.Eventually some chromed bores develope into mighty fine shooters equal to any other bbl. There are lots of variables in any gun bore actually.

 

[TMiller556]

Oh okay I get it now. So the uneven bore causes gas leakage and velocity variations? And Thanks for the replies everyone

 

[Welding Rod]

I have a chrome lined RRA that is a sub MOA shooter. I guess it would have been really accurate without the chrome.

 

[CraigC]

For hardchromed barrels they cut the bore oversize and then plate it back to the correct dimension. Chrome can build up unevenly in both cross section and though the bore's length.

We have a winner! The problem is that chrome tends to not cover the surface evenly and puddles in areas. The "problem" is not universal and obviously some barrels will shoot better than others. My chrome lined M&P15 shoots MOA but you won't find any match rifles with chrome lined bores. It's for protection against erosion during automatic fire, not accuracy.

 

[Lonerider357]

I personally wouldn't shoot for MOA, I aim for MOP !!!





Middle Of Perp !!

 

[Shadow 7D]

Quality Chrome is carefully applied
it isn't bumper shop, and yeah it's not going to be same as a cut rifle, hand lapped, custom barrel, but then those 'shoot out' in what 500 rounds?

Chrome is for barrels that do 500 rounds a minute.

 

[hardluk1]

Shadow 7D Oh so very true.

 

[CraigC]

Quality Chrome is carefully applied...

I think we all know there's a big difference between industrial hard chrome and automotive decorative chrome. It doesn't really matter how carefully applied it is. Though I'm sure there are shops who do it better than others. It's simply the nature of the material. Nickel flows and adheres much more evenly but is not hard enough for bore lining.

 

[Slamfire]

I think chrome barrels are better than they used to be. I have a chrome lined barrel in my Armalite M4 and it shoots very well.

A good modern chrome lined barrel will shoot inside the hold of 99% of the shooters out there, for hunting and rock busting they are perfectly fine.

I knew one HM Distinguished shooter who loved Colt chrome lined barrels on his service rifles. He was shooting across the course and all you have to do is shoot 2 MOA to have a perfect score. I don't know when anyone ever shot a perfect score all the way out, which shows that the shooter, not the barrel, is the limiting factor in NRA highpower.

Unless you are one of the best shooters in the US, I would not worry about the accuracy of a good chrome lined barrel as it will shoot well enough for most needs.

 

[dom1104]

http://www.ar15.com/mobile/topic.html?b=3&f=118&t=489698&page=1

An interesting thread related to this subject.

 

[FlyinBryan]

own 2 chrome lined bushmaster barrels and both shoot 5 shots into less that 1" @100 yds

 

[Ar180shooter]

For hardchromed barrels they cut the bore oversize and then plate it back to the correct dimension. Chrome can build up unevenly in both cross section and though the bore's length.

That said, modern (as opposed to WWII era) metal plating is pretty good.

BSW

Exactly, well said.

It's not that chrome lined barrels can't shoot well, but the process does not help in making a superbly accurate barrel. I have a Swiss Arms Classic Green (basically a Sig 540 re-engineered to Sig 550 specifications to make it legal for the Canadian market) that will shoot sub MOA (best group to date is 0.6 MOA @ 200 yards), and it has a chrome lined barrel and a long stroke gas system. Why is this? Because the barrel is only one small piece of the accuracy puzzle. Many other things like the type of gas system, chamber specifications, ammunition used, optics used, optics mounts, trigger, etc. all have bearing on accuracy. Admittedly, the barrel is one of the most important pieces, but a well made chrome lined barrel is still very capable of printing good groups.

 

[mtrmn]

"Why are chrome lined barrels less accurate?"

In my opinion- They're not.
I can't shoot the difference. Maybe a bench rest shooter could tell a difference, but I don't think any normal shooter would ever be able to definitively lay any blame on the chrome and PROVE it.

 

[Panzercat]

Chrome isn't inherently less accurate, but it highly dependent on the application process since it magnifies any flaws in the bore.

 

[helotaxi]

It is inherently less consistent which is inherently less accurate. Whether that difference can be realized by the shooter is a different discussion. For most the answer is that it doesn't matter.

 

[nathan]

I noticed my Norinco SKS wasnt grouping very well so i cleaned it with Barnes Copper Remover. Next time at the range it grouped more tighter. In my opinion it may or may not on the OPs question. Most important is whether the copper built up needed to be removed then accuracy returns

 

[Panzercat]

It is inherently less consistent which is inherently less accurate. Whether that difference can be realized by the shooter is a different discussion. For most the answer is that it doesn't matter.

Bullpucky. Its a process like any other dependent on the skill of those applying it and the base quality of the barrel its being applied to. There have already been several upon several threads concerning chrome lined barrels and it not 'inherent less consistent' unless the quality of your manufacturing is 'inherently less consistent'.

 

[WardenWolf]

I suspect another aspect is that chrome is much more resistant to wear, and thus chrome-lined barrels take a lot longer to properly break in. In a normal barrel, minor imperfections will be worn off relatively quickly. Chrome-lined barrels take a lot more rounds downrange to reach this same point.

 

[helotaxi]

Bullpucky. Its a process like any other dependent on the skill of those applying it and the base quality of the barrel its being applied to. There have already been several upon several threads concerning chrome lined barrels and it not 'inherent less consistent' unless the quality of your manufacturing is 'inherently less consistent'.

If the finished bore diameter could be as well controlled on a chrome lined barrel as it can on an unlined chromoly or stainless barrel, then long range and benchrest match shooters would ALL use chrome lined barrels since they are more resistant to wear and their fantastic barrel would last longer. The simple fact is that NO benchrest or long range match shooters use chrome lined barrels for the simple reason that it is impossible to get the thickness of the chrome layer exact. Again, the vastly overwhelming majority of shooters will never be able to tell the difference, but for those who can it is a significant difference.