I don't understand copper fouling
- Thread starter Thejunk07
- Start date
dakota.potts
New member
Any time two things touch each other, they will both trade material.
It's my understanding that copper fouling is when copper from a clad bullet rubs off inside the bore of your gun. Over time, the little bit that rubs off will build up and can affect accuracy.
It's my understanding that copper fouling is when copper from a clad bullet rubs off inside the bore of your gun. Over time, the little bit that rubs off will build up and can affect accuracy.
In general, the more shots fired, the more copper fouling buildup.
It depends on a lot of things, the smoothness/roughness of the bore being the most salient factor. Some guns will build up copper fouling very quickly, some seem to almost be immune to the problem.
There are a number of things that can be done to reduce or prevent copper fouling.
Lapping the bore makes the bore much smoother and that can cause a significant reduction in the tendency of a gun to copper foul.
Some people say that using a bore break-in procedure will perform a similar function to lapping the bore, although it's probably not going to be as effective as lapping would be.
Simply cleaning the bore thoroughly (including the complete removal of all copper fouling) after every trip to the range will present a clean bore to the next few bullets that travel down the bore. That can result in the bore being smoothed out over time. Basically the same kind of effect that a barrel break-in procedure is supposed to perform.
There are new powders available that have properties that discourage copper fouling and may actually remove copper fouling over time. Those would only be available to handloaders.
There are a number of ways to remove copper fouling, the simplest is probably using a good copper solvent when cleaning the bore. Another relatively simple method employs a bore paste that contains a very mild abrasive which polishes the copper away. There are also products which remove the copper fouling using a reverse electro-plating technique.
Copper fouling is not an indication that the rifle's useful life is coming to an end. It's just a fact of shooting like recoil or normal fouling buildup.
And it is not always a bad thing. Most rifles do not shoot as accurately with a perfectly clean barrel as they do with one that has some fouling in the barrel. Especially common factory barrels. I find that 6-10 shots need to be fired through a barrel after a thorough cleaning before accuracy returns to normal. Once too much fouling builds up accuracy will start to drop off. That could be 50 rounds, or several hundred depending on the barrel.
Very few products actually remove jacket fouling. Most loosen the grip & the brush scrubs them out!
2 that I have used & can reccomend to remove fouling without scrubbing or risking bore damages (as is caused with many strong ammonia-based products) are the M-Pro-7 copper remover (used in conjunction with M-pro-7 gun cleaner) & the other is KG-12 Big Bore. Both chemically dissolve jacket metal with minimal scrubbing & can be left in for extended periods for stubborn fouling with no harm to the barrel.
The M-pro-7 claims to reduce fouling if used as directed & left in the bore.
If you check out the website they do a great description of fouling, both powder & metal, & how it is removed.
http://www.mpro7.com/m-pro7-guide.html
2 that I have used & can reccomend to remove fouling without scrubbing or risking bore damages (as is caused with many strong ammonia-based products) are the M-Pro-7 copper remover (used in conjunction with M-pro-7 gun cleaner) & the other is KG-12 Big Bore. Both chemically dissolve jacket metal with minimal scrubbing & can be left in for extended periods for stubborn fouling with no harm to the barrel.
The M-pro-7 claims to reduce fouling if used as directed & left in the bore.
If you check out the website they do a great description of fouling, both powder & metal, & how it is removed.
http://www.mpro7.com/m-pro7-guide.html
Copper fouling is when streaks of copper are left on your bore.
This affects accuracy in two ways. The first of which is it mechanically changes the dimensions of the bore a tiny bit. The second is that it changes the coefficient of friction between the bullet and the bore between shots as more copper builds up.
The second reason can be explained by the rule of thumb for metal friction is that alike is worse than different. Metals that are alike will gall quicker than metals that are different.
Both methods of action start screwing with pressure, bore time, and therefore harmonics.
To deal with this you need to clean the copper from your bore before it builds up to the point where it affects accuracy. You can do this manually by cleaning, using ammunition with a powder that has a decoppering agent (such as tin dioxide) added, or using open base bullets where the lead is exposed (lead vapor from the base of the bullet will bond with hot copper to form a brittle compound that easily falls off the bore on the next shot).
Using open base FMJ ammunition will not fully eliminate copper streaking, but in my experience you will not get a serious degradation of accuracy as all you will get is a little streaking. Sometimes you can see it as "copper wash" around the muzzle.
Hope this helps.
Jimro
This affects accuracy in two ways. The first of which is it mechanically changes the dimensions of the bore a tiny bit. The second is that it changes the coefficient of friction between the bullet and the bore between shots as more copper builds up.
The second reason can be explained by the rule of thumb for metal friction is that alike is worse than different. Metals that are alike will gall quicker than metals that are different.
Both methods of action start screwing with pressure, bore time, and therefore harmonics.
To deal with this you need to clean the copper from your bore before it builds up to the point where it affects accuracy. You can do this manually by cleaning, using ammunition with a powder that has a decoppering agent (such as tin dioxide) added, or using open base bullets where the lead is exposed (lead vapor from the base of the bullet will bond with hot copper to form a brittle compound that easily falls off the bore on the next shot).
Using open base FMJ ammunition will not fully eliminate copper streaking, but in my experience you will not get a serious degradation of accuracy as all you will get is a little streaking. Sometimes you can see it as "copper wash" around the muzzle.
Hope this helps.
Jimro
green_MTman
New member
most people get it out by getting a heavy duty copper solvent.then run several heavely soaked patches through.
let it soak for 30 minutes,then begin to run dry patches and a few more wet patches.
when you no longer see any blue or green on the patches the copper is gone
let it soak for 30 minutes,then begin to run dry patches and a few more wet patches.
when you no longer see any blue or green on the patches the copper is gone
Good info above.
Copper fouling- or lack of it- is the reason many rifles have a different p.o.i. after cleaning copper fouling, and it can take anywhere from a few, to a dozen or more shots to lay down the correct amount of fouling to restore accuracy.
Do a search, lots of choice on what to use, and how to remove, copper fouling.
All our barrels are aftermarket and require only a few shots after cleaning to get back to where they need to be, so being lazy and not one to use brushes, I use Wipe-Out foaming bore cleaner to remove both powder and copper fouling.
Copper fouling- or lack of it- is the reason many rifles have a different p.o.i. after cleaning copper fouling, and it can take anywhere from a few, to a dozen or more shots to lay down the correct amount of fouling to restore accuracy.
Do a search, lots of choice on what to use, and how to remove, copper fouling.
All our barrels are aftermarket and require only a few shots after cleaning to get back to where they need to be, so being lazy and not one to use brushes, I use Wipe-Out foaming bore cleaner to remove both powder and copper fouling.
jmr40
I too have experienced this with several rifles, and found it most noticeable in rimfire rifles that I've owned.(Not copper fouling, but same exact concept)
For me personally, I clean all of my rifles the same way, which is after every range/hunting trip. I use powder solvent in the barrel w/brush and patches, clean the action, and oil or grease moving parts as needed.
If I notice accuracy starting to drop off, I will use Sweet's 7.62 bore cleaner and clean the copper out of the bore. That stuff works really well, but smells terrible(ammonia). Make sure you are in a well ventilated area.
I too have experienced this with several rifles, and found it most noticeable in rimfire rifles that I've owned.(Not copper fouling, but same exact concept)
For me personally, I clean all of my rifles the same way, which is after every range/hunting trip. I use powder solvent in the barrel w/brush and patches, clean the action, and oil or grease moving parts as needed.
If I notice accuracy starting to drop off, I will use Sweet's 7.62 bore cleaner and clean the copper out of the bore. That stuff works really well, but smells terrible(ammonia). Make sure you are in a well ventilated area.
With a factory rifle, I used a Copper cleaner & JB Compond followed with Kroil oil. A factory barrel most of the time are rougher then match grade, so the copper will scrape off the bullet easier, Thats why the JB Compond worked great for me. I cleaned my rifle every time I shot it. Got very accurate 4000+ rounds out of the stock barrel. Changed to a match grade SS barrel, no need to use JB Compond due to the barrel is much smoother, hardly any fouling. Now clean with KG-1 & KG-12 followed by Hoppe's#9 dry patch then Kroil oil. Hope I helped
stubbicatt
New member
Another product I have had good success with is that foamy Wipe Out bore cleaner.