Managing Copper Fouling

Hey Riflechair what is Copper Fouling and why do I care?


Copper Fouling is caused by copper jacket bullet material being left in the barrel after each firing

1. Copper is soft and malleable and eventually lines your barrel (copper fouling tends to accumulate on the rifling first)

Copper fouling is accumulative and builds with every shot fired where-as Powder residue will accumulate to a certain point and then stabilize.

Copper fouling turns green once oxidation takes place - a active sign of corrosion. Galvanic Corrosion takes a serious toll on your bore
I've produced a presentation to instruct this material which I am happy to share with you.     

printable adobe reader pdf (1.1 MB)

Should I take copper fouling seriously?
YES! Copper fouling is cumulative with every shot you make! Imagine all of the years of use, the hundreds (perhaps thousands) of rounds expended and you haven't effectively removed any of this fouling yet? You need solvents designed to remove copper - CLP does not do this for you.


The rate of copper fouling has a lot to do with bore condition

• Clean and well maintained barrels foul less than dirty bores
• Barrels free from corrosion and pitting foul less
• Smooth bores accumulate less copper than rough bores

Internal and Exterior Ballistics

• Chamber Pressure increases as the bore fouls
• As chamber pressure increases POI will rise (example: water fouled bore)
• Barrels sufficiently obstructed by copper and corrosion can cause severe pressure spikes and potentially pose a safety hazard (No4 pressure limit is 40,000 psi)
• Badly fouled bores incur drag on the bullet and negatively impacts velocity
• As grooves are filled with copper there is less purchase for the rifling to grasp the bullet and rate of twist is impacted (1:10 twist).
• Reduced twist results in bullet de-stabilization upon breaching the sound barrier (bullet goes subsonic) resulting in cavitation and tumbling at long ranges

I have seen bores so badly copper fouled that the rifling grooves are almost completely colluded. Can you imagine the extreme pressure spike these actions must be enduring with every shot? Think of the recoil those sore shoulders must be needlessly receiving!


From a safety and a performance perspective copper fouling will have a serious impact on your shooting. I highly recommend you read the material I am providing and give serious consideration to paying more attention to managing copper fouling in your rifle.

The downloadable information provided above is supposed to supplemented by a presenter (me). However as I can't be in your living room to review it with you the raw presentation will have to suffice.

Tip of the Day: Her Majesty Queen Elizabeth II has issued you one of her service rifles and the expectation is that you take proper care of it. Clean that rifle with pride and make that bore shine. What would you do if Sergeant Major Fozzard was to perform a suprise rifle inspection tomorrow? The condition of your rifle says a lot about who you are to the NCO performing the inspection. What kind of impression would you want to make?