does anyone know if the phenominum of copper eqilibrium [copper build up in the bore across a number of rounds - generally several hundred - where a barrel's accuracy reaches it's full potential] applies to .22 rimfire target rifles shooting copper coated rounds as it does to centerfire?
copper equilibrium
- Thread starter truenorth777
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To the best of my knowledge copper only hurts accuracy. In a good hand lapped barrel very little copper will be retained in the barrel of a centerfire. The break in of shooting a round, removing the copper, and shooting another round, etc. is designed to smooth out the barrel so it doe not retain any significant copper. A poor barrel with the wrong surface finish, will probably never "break in" and will always retain copper. That is not a good thing, and accuracy usually suffers.
On rimfires that flash coat of copper on the bullet is just for show. It does nothing. Copper build up in a rimfire is highly unlikely to be a problem. Any time I have used copper cleaner in my rimfire, I fail to detect any copper at all, even when shooting the cheap copper coated plinker stuff.
Look up Sniper 101 or Tiberaurous Rex on youtube, I'm pretty sure he has a video or two talking about copper equilibrium. It made sense to me when I watched it. It think it's also the reason a lot of shooter don't clean their barrels for several hundred rounds.
seen that too. just wondered if it might apply to a .22 rifle?
If I remember right he talks about lead as well. Been a while since I watched them so I'm not certain and I can't pinpoint exactly which episode it was in. Go thru his vids. Look for anything barrel bore, ballistic, cleaning or fouling. Watch em all...good stuff.
That copper fouling could improve consistency seems counter intuitive. I am told that short range bench rest competitors that require extreme consistency, clean frequently...sometimes even during the course of a match. This implies that keeping the bore copper free is important and where accuracy falling off a few hundredths of an inch can lose a match...is important. I think the phrase "accuracy falling off" means different things to different shooters, and is related to expectations. Perhaps with some types of shooting by some shooters, the deterioration of consistency is not so noticiblle?
Definitely check out his channel and Sniper 101 series, a lot of very good information from Rex.
No. People who shoot .22lr target/match rifles don't usually shoot junk ammo in their rifles, so not a problem.
Lapua, Eley, that's about it if you want accuracy and not risk screwing up your barrel, and yes I've heard of a few good match rifles being screwed up by people shooting junk in them.
Now if your target rifle is really just some basic $200 thing, shoot whatever you want, although good ammo will always do better even in those.
Good .22 ammo is fairly waxy, no uncommon to need 10-20+rounds to get things to smooth out, some clean more than others, whatever works for that shooter.
Lapua, Eley, that's about it if you want accuracy and not risk screwing up your barrel, and yes I've heard of a few good match rifles being screwed up by people shooting junk in them.
Now if your target rifle is really just some basic $200 thing, shoot whatever you want, although good ammo will always do better even in those.
Good .22 ammo is fairly waxy, no uncommon to need 10-20+rounds to get things to smooth out, some clean more than others, whatever works for that shooter.
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The "copper wash" used by some manufacturers of .22 ammo is a lube. Other common lubes are either "grease" or wax based. It is not uncommon to get best consistency after 20 shots or so with a particular ammo as it can take that long to purge any other lube and coat the bore with the "new" type of lube. Lead has lubrication properties itself.
I think the copper wash coating is more common with "sports grade" ammo as it has less tendency to collect lint/dirt in pockets.
I think the copper wash coating is more common with "sports grade" ammo as it has less tendency to collect lint/dirt in pockets.
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In my opinion Yes it does apply.
Yes. In general it is a reflection of barrel finish quality in centerfire rifles. Hand lapped precision barrels from custom barrel makers tend not to pick up copper. Cheap, poorly finished barrels will copper foul. See this article from Dan Lilji of Lilja Barrels. Copper fouling is not an issue in rimfires.
The following is correct, as is comment from Ron AKA - top shooters such as the GB Rifle Team do not clean frequently during matches because they do not have to. They use Krieger and Bartlein, possibly some Kolbe, which do not foul as quickly as barrels with inferior finishes.
Quote Originally Posted by Evil_Dark View Post
I think, based on my "little" experience, that every barrel is different on copper fouling. If you are Lucky, yours wont' build up that much. One other can be fouling as hell and affect accuracy after 100 shots...
Yes. In general it is a reflection of barrel finish quality in centerfire rifles. Hand lapped precision barrels from custom barrel makers tend not to pick up copper. Cheap, poorly finished barrels will copper foul. See this article from Dan Lilji of Lilja Barrels. Copper fouling is not an issue in rimfires
Quote Originally Posted by Evil_Dark View Post
I think, based on my "little" experience, that every barrel is different on copper fouling. If you are Lucky, yours wont' build up that much. One other can be fouling as hell and affect accuracy after 100 shots...
Yes. In general it is a reflection of barrel finish quality in centerfire rifles. Hand lapped precision barrels from custom barrel makers tend not to pick up copper. Cheap, poorly finished barrels will copper foul. See this article from Dan Lilji of Lilja Barrels. Copper fouling is not an issue in rimfires
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Regarding center fire, I think this occurs in stages and it's why predicting the CCB shot is a fallacy.
I have yet to have a rifle that shoots predictably for the first few rounds after a thorough and proper cleaning. I'll repeat myself for clarity... after a thorough and proper cleaning. Many experienced shooters are aware of this and its why we insist upon a blowoff period at the start of each day during an F Class match.
To describe my interpretation, starting with a very clean barrel with no copper present, the first bullet going down the barrel has copper to clean steel contact. Some of the copper is deposited to the barrel after the shot and the next round has contact between copper and steel with some copper plating.
The "coefficient of friction" between the bullet and the barrel changes as copper content inside the barrel changes.
Shot after shot the copper coverage increases in high stress areas of the rifling until an equilibrium is created. In my experience critical mass takes about 3 to 5 rounds with a good barrel.
After these 5 rounds copper foul the barrel, everything tends to settle down and the rifle will shoot about as it should for the next 50 to 100 rounds. After that, and depending greatly upon the smoothness of the barrel and hotness of the load, things tend to degrade and a good cleaning is again required.
In some cases, and typically with not so good barrels, they actually begin to shoot better after not being cleaned for several hundred rounds. This is because the barrel is getting smaller, tighter and possibly even smoother as copper accumulates on the inside.
As for a good predictable CCB shot I think there is no such thing, but you can have a predictable CB shot. If you want a predictable cold bore shot, the barrel should specifically not be "clean".
Just my opinion.
I have yet to have a rifle that shoots predictably for the first few rounds after a thorough and proper cleaning. I'll repeat myself for clarity... after a thorough and proper cleaning. Many experienced shooters are aware of this and its why we insist upon a blowoff period at the start of each day during an F Class match.
To describe my interpretation, starting with a very clean barrel with no copper present, the first bullet going down the barrel has copper to clean steel contact. Some of the copper is deposited to the barrel after the shot and the next round has contact between copper and steel with some copper plating.
The "coefficient of friction" between the bullet and the barrel changes as copper content inside the barrel changes.
Shot after shot the copper coverage increases in high stress areas of the rifling until an equilibrium is created. In my experience critical mass takes about 3 to 5 rounds with a good barrel.
After these 5 rounds copper foul the barrel, everything tends to settle down and the rifle will shoot about as it should for the next 50 to 100 rounds. After that, and depending greatly upon the smoothness of the barrel and hotness of the load, things tend to degrade and a good cleaning is again required.
In some cases, and typically with not so good barrels, they actually begin to shoot better after not being cleaned for several hundred rounds. This is because the barrel is getting smaller, tighter and possibly even smoother as copper accumulates on the inside.
As for a good predictable CCB shot I think there is no such thing, but you can have a predictable CB shot. If you want a predictable cold bore shot, the barrel should specifically not be "clean".
Just my opinion.
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Copper accumulates in all barrels and it's just a matter of opinion as to what amount constitutes "fouled".
The velocity changes as copper accumulates inside the barrel. At 100 yards the effect of velocity change I mentioned above caused by varying degrees of copper accumulation would be irrelevant. At long range even 15 FPS will take you out of the match.
This is just a matter of what kind of precision shooting you do. What matters to a 100 yard BR guy is often very different from a 1000 yard F-Class or BR shooter.
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This is just a matter of what kind of precision shooting you do. What matters to a 100 yard BR guy is often very different from a 1000 yard F-Class or BR shooter.[/QUOTE]
Agreed , at 100-300 it's copper that will cause fliers and take you out of the match .
Agreed , at 100-300 it's copper that will cause fliers and take you out of the match .
A good copper solvent like Barnes CR-10 will quickly tell you if you have a copper problem in a centerfire. Just wrap a white patch around a nylon brush and put it through the bore. If it turns blue, you have copper. I have never found copper in my rimfire.
