I've found very few companies that offer to hard chrome (or any other coating/finish) the bore of a firearm. What are the dangers/drawbacks to aftermarket chroming a barrel bore? Will it affect accuracy? Decrease bore diameter enought to cause eexcessive pressure when firing the weapon?
chrome bore - disadvantages?
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kevindsingleton
Member
Unless the barrel was in new, unfired condition, I'd think the likelihood of getting any treatment to reliably stick would be questionable, and, if I were the plating shop, I don't think I'd want to take on the liability for what you'd be willing to pay for the work.
Maybe you should ask those companies who declined to do the job why they refused.
Maybe you should ask those companies who declined to do the job why they refused.
NonConformist
member
Chrome lined barrels from a factory are fine, albeit slightly less accurate than a non line barrel, AFA aftermarket job, Id avoid them myself just in case they dont do it right.
Just buy a Chrome Lined Barrel from a reputable maker and install it, or have it installed.
Advantages are durability, ease of cleaning, no break in required etc;
Just buy a Chrome Lined Barrel from a reputable maker and install it, or have it installed.
Advantages are durability, ease of cleaning, no break in required etc;
The Lone Haranguer
Member
I would guess that if you apply plating to a bore and/or chamber of a barrel that was not originally designed to be hard-chromed, it will reduce the interior dimensions and cause problems with feeding or pressure.
matrem
Member
The way I've understood it,since plated barrels have to start out bigger(room for plating) & plating technology isn't able to plate a barrel to the consistency that they can be machined,there is a potential for accuracy loss.
Potential being the key word.
Potential being the key word.
Old Grump
Member
So cut the rifling again with a slightly larger die, if somebody plates a lot of bores he probably has the dies already or a gunsmith who makes his own barrels can probably do it.
Crow1108
Member
From what I understand, you have to be careful with what cleaners you use for it. IIRC, ammonia based cleaners mess up the chrome.
Cesiumsponge
Member
I don't think industrial chrome plate can be applied in very thin layers under 0.0005" and as you build up the thickness, it isn't going to retain those sharp, crisp edges on the lands and grooves. I am not certain what typical thicknesses are called out on firearm barrels.
There are other types of plating which are even harder and even lower in friction, and can be applied much thinner, though haven't found their way into the firearms industry yet. Most of the high end finishes start in aerospace and military and trickle down to more mundane commercial purposes.
Several times we've had to send round aerospace parts out for industrial chrome plating. If it's applied thick enough, it ends up being sent out for centerless grinding to bring back to tolerance and uniformity. It's hard to grow thick coatings of stuff and keep it all uniform due to so many variables.
As mentioned, any parts that are specifically cited for plating are machined so overall there is less material (larger inside dimensions, smaller outer dimensions), because plating will bring it back into specified tolerances.
There are other types of plating which are even harder and even lower in friction, and can be applied much thinner, though haven't found their way into the firearms industry yet. Most of the high end finishes start in aerospace and military and trickle down to more mundane commercial purposes.
Several times we've had to send round aerospace parts out for industrial chrome plating. If it's applied thick enough, it ends up being sent out for centerless grinding to bring back to tolerance and uniformity. It's hard to grow thick coatings of stuff and keep it all uniform due to so many variables.
As mentioned, any parts that are specifically cited for plating are machined so overall there is less material (larger inside dimensions, smaller outer dimensions), because plating will bring it back into specified tolerances.
Loosedhorse
member
Not so far--in fact just the opposite.
Few years back I find a Benelli M1 Super 90--pistol grip, long mag tube--on the used shelf for what seems a ridiculously low price. I ask about it, he says it's a "police turn-in; it's pretty worn."
I look it over. Sure enough, the chrome on the bolt face is gone, and the barrel looks black, not one bit of chrome. But, mechanically, it looks sound. I walk out with it.
As always, first thing I do when I get home is break it down and clean it. (BTW--can ANYONE get that mag tube off?) It's filthy, no sign its ever been violated by a cleaning rod. I mean it.
After I get the receiver and bolt cleaned up and oiled, I grit my teeth and start on the barrel. And a funny thing happens--I begin to see a little chrome. And then a little more.
G-d know how much solvent later, I've got lots and lots of plastic-filled patches; but I'm looking at a barrel so shiny it's like a kaleidoscope as I peek through it and swing it around the room. And, probably from all the solvent fumes, I've got a big, stupid grin on my face.
Took it to the range. Doesn't like birdshot or reduced loads, but with slugs or any standard buckshot (4 to 00), zingo!--no problems. We agreed on 1 buck after patterning. It now wears a flashlight and is within easy reach at bedtime.
So, no, no problems with chrome-lined barrels for me!
Few years back I find a Benelli M1 Super 90--pistol grip, long mag tube--on the used shelf for what seems a ridiculously low price. I ask about it, he says it's a "police turn-in; it's pretty worn."
I look it over. Sure enough, the chrome on the bolt face is gone, and the barrel looks black, not one bit of chrome. But, mechanically, it looks sound. I walk out with it.
As always, first thing I do when I get home is break it down and clean it. (BTW--can ANYONE get that mag tube off?) It's filthy, no sign its ever been violated by a cleaning rod. I mean it.
After I get the receiver and bolt cleaned up and oiled, I grit my teeth and start on the barrel. And a funny thing happens--I begin to see a little chrome. And then a little more.
G-d know how much solvent later, I've got lots and lots of plastic-filled patches; but I'm looking at a barrel so shiny it's like a kaleidoscope as I peek through it and swing it around the room. And, probably from all the solvent fumes, I've got a big, stupid grin on my face.
Took it to the range. Doesn't like birdshot or reduced loads, but with slugs or any standard buckshot (4 to 00), zingo!--no problems. We agreed on 1 buck after patterning. It now wears a flashlight and is within easy reach at bedtime.
So, no, no problems with chrome-lined barrels for me!
I'm not aware of any refinishing companies that will chrome the bore or chamber of an existing firearm...
That said.
Ammonia cleaning solvents should not harm hard chrome applied to steel, but decorative chrome or hard chrome applied to some other metals may have a strike layer (undercoating) of copper which can be damaged by ammonia cleaning solvents. If there are cracks or minute imperfections in the chrome the solvent could migrate under the chrome and attack the undercoating causing the chrome to peel.
Chrome-lined barrels CAN be made very accurate, but it seems that there hasn't been a huge effort to figure out how in the U.S. I recall reading a review of a Russian .308 bolt action rifle with a chrome-lined bore that shot close to 0.5 MOA at 600 yards. I think it was a review by D. Fortier in the SGN but it's been a few years. At any rate, chrome & accuracy are not incompatible, but for whatever reason our accuracy gurus in the U.S. don't feel the need to make it happen.
That said.
Ammonia cleaning solvents should not harm hard chrome applied to steel, but decorative chrome or hard chrome applied to some other metals may have a strike layer (undercoating) of copper which can be damaged by ammonia cleaning solvents. If there are cracks or minute imperfections in the chrome the solvent could migrate under the chrome and attack the undercoating causing the chrome to peel.
Chrome-lined barrels CAN be made very accurate, but it seems that there hasn't been a huge effort to figure out how in the U.S. I recall reading a review of a Russian .308 bolt action rifle with a chrome-lined bore that shot close to 0.5 MOA at 600 yards. I think it was a review by D. Fortier in the SGN but it's been a few years. At any rate, chrome & accuracy are not incompatible, but for whatever reason our accuracy gurus in the U.S. don't feel the need to make it happen.
elsullo
Member
Me like chrome bore!
I have two, both of which are VERY accurate: I have a Daewoo DP51 9mm which comes with a chromed barrel; and a Glock 19 with an aftermarket chromed polygonal barrel and slide. Simply perfect performance from both.
You may have noticed that the Beretta 92 9mm, the official sidearm of the "Free World", has a chromed-lined barrel? Need we consider the M-16 and the AK-47, both with chrome-lined barrels.
The point? Easy clean, and long-time-no-clean...................elsullo
I have two, both of which are VERY accurate: I have a Daewoo DP51 9mm which comes with a chromed barrel; and a Glock 19 with an aftermarket chromed polygonal barrel and slide. Simply perfect performance from both.
You may have noticed that the Beretta 92 9mm, the official sidearm of the "Free World", has a chromed-lined barrel? Need we consider the M-16 and the AK-47, both with chrome-lined barrels.
The point? Easy clean, and long-time-no-clean...................elsullo
RockyMtnTactical
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There are not really any drawbacks so long as it is done correctly.
expeditionx
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From the Bushmaster website faqs:
"Then, after the barrel is fully machined, it is chrome lined, making it even tougher yet - and virtually impervious to rust or erosion. This chroming process isn't like car bumper chroming. It actually welds each chromium molecule to the steel bore. This chrome lining is far more resistant to wear than a bare steel bore and it gives slightly increased velocity due to the lubricity ("slipperiness") of the chrome. And, you'll see less fouling and easier cleaning with a chrome lined barrel - all in all, a superior product."
Chrome lining is not exactly the same as common plating.
If you plate your bore like a bumper, the plating will shear off
and could potentially obstruct the bore causing a barrel
explosion. Factory bore lining is very thin and the bond is
far stronger than the shearing forces of the bullet. Even
guns like the remington 870 marine magnum with the electroless
nickle coating is not plated like a conventional bumper.
As good as the electroless nickle coating is, I'm not sure
that it could be offered in a centerfire rifle bore which has
far more projectile speed and cartridge pressure.
Avoid plating the bore. Its dangerous. Only factory lined
barrels are set up right. Nitriding the bore might be your
better solution.
"Then, after the barrel is fully machined, it is chrome lined, making it even tougher yet - and virtually impervious to rust or erosion. This chroming process isn't like car bumper chroming. It actually welds each chromium molecule to the steel bore. This chrome lining is far more resistant to wear than a bare steel bore and it gives slightly increased velocity due to the lubricity ("slipperiness") of the chrome. And, you'll see less fouling and easier cleaning with a chrome lined barrel - all in all, a superior product."
Chrome lining is not exactly the same as common plating.
If you plate your bore like a bumper, the plating will shear off
and could potentially obstruct the bore causing a barrel
explosion. Factory bore lining is very thin and the bond is
far stronger than the shearing forces of the bullet. Even
guns like the remington 870 marine magnum with the electroless
nickle coating is not plated like a conventional bumper.
As good as the electroless nickle coating is, I'm not sure
that it could be offered in a centerfire rifle bore which has
far more projectile speed and cartridge pressure.
Avoid plating the bore. Its dangerous. Only factory lined
barrels are set up right. Nitriding the bore might be your
better solution.
IndianaBoy
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- Jan 3, 2005
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- 1,551
The theory that chrome lined bores are less accurate is... well... theoretical.
A benchrest shooter might be able to tell the difference. A guy firing his carbine offhand will never be able to.
It's not like chrome lining a bore will make an AR into a 4 MOA or worse gun. my chromed carbine shoots great. The bore cleans up easy and it will have a longer life.
Unless you are a serious target shooter, get the chromed bore.
A benchrest shooter might be able to tell the difference. A guy firing his carbine offhand will never be able to.
It's not like chrome lining a bore will make an AR into a 4 MOA or worse gun. my chromed carbine shoots great. The bore cleans up easy and it will have a longer life.
Unless you are a serious target shooter, get the chromed bore.
plexreticle
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- Oct 8, 2006
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I'll take a chrome lined any day given the choice.
moooose102
Member
i do not have an ar style gun yet. but when i do get one, it will have a chrome bore barrel. as far as plating an existing barrel, forget it. all those tiny little microscopic poors have been contaminated, and you will never be able to get them clean enough for propper bonding. also, the chrome lined barrels have to be made ever so slightly oversized to allow for the plating thickness. even if the plating is .0005" thick. if your barrel was on the large size to begin with, you might be ok, but if it was on the tight side of specs, you would have a disaster waiting to happen. if you want a chrome barrel, buy a chrome barrel. if your bore is exceptionally rough for one reason or another, buy a box of David Tubbs Final Finish System bullets and shoot all 50 of them. i did it to my 45/70 a little while ago. WHAT A DIFFERENCE! you could see the chatter marks with your bare eyes before, and after, it was very smooth and shiney. kind of like the difference between 60 grit sand paper and 1200 grit. not as smooth as chrome, but way, way smoother. i probably will not do this to every rifle i own, as most of my rifles have many, many rounds through them. my 45/70, while not a virgin, only had a hundred rounds or so through it.
preventec47
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The use or need for chrome barrels disappeared when stainless
steels began to be used. In fact chrome is one of the component
alloys along with nickle in the stainless steel barrels. That said,
I must say I have a WW-II Jap 7.7 that had rust flaking off the
outside of the barrel that I cleaned up and when I cleaned
what looked like mud and tar and axle grease out of the barrel
the bore looks as good as any brand new rifle I have ever looked
in. The JAPS in WW-II must have figured out how to do it
because from the muzzle end the chrome lining in the barrel
looks pretty thick.
steels began to be used. In fact chrome is one of the component
alloys along with nickle in the stainless steel barrels. That said,
I must say I have a WW-II Jap 7.7 that had rust flaking off the
outside of the barrel that I cleaned up and when I cleaned
what looked like mud and tar and axle grease out of the barrel
the bore looks as good as any brand new rifle I have ever looked
in. The JAPS in WW-II must have figured out how to do it
because from the muzzle end the chrome lining in the barrel
looks pretty thick.
Having cleaned a good number of both chromed & stainless barrels I would say that chrome-lined barrels clean up faster than stainless.
Also a chrome-lining is a good deal harder than stainless (even though stainless steels typically contain chrome) and will therefore last much longer.
Stainless was a big step, but it's an alternative to chrome, not an improvement to it, in my opinion.
Also a chrome-lining is a good deal harder than stainless (even though stainless steels typically contain chrome) and will therefore last much longer.
Stainless was a big step, but it's an alternative to chrome, not an improvement to it, in my opinion.
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