Every round you fire leaves more than just powder residue behind. With each shot, copper from the bullet jacket transfers onto the rifling inside your barrel. Over time, this copper fouling builds up, affecting your rifle’s accuracy and making future cleaning far more difficult. 

For UK shooters who value precision and consistency — whether on the range, in the field, or on the hill — proper barrel care is essential. That’s where Bore Tech CU+2 Copper Remover, available from Shooting Sports UK, proves its worth. 

 

What Is Copper Fouling? 

Most rifle ammunition used in the UK — from stalking rounds like .243 Win and .308 Win to target calibres such as 6.5 Creedmoor — uses copper-jacketed bullets. When fired, friction and heat cause microscopic traces of copper to coat the barrel’s bore. 

If not removed, this fouling can: 

• Reduce accuracy by altering the bore surface and disrupting bullet travel 
• Trap carbon and powder residue, creating stubborn build-up 
• Make subsequent cleaning harder, requiring more aggressive methods 
• Affect barrel life if left unchecked over thousands of rounds 

You’ll know it’s time for a deep clean when you see blue or green staining on patches, or when groups start to open up on the target. 

 

Which Firearms Need Copper Removal? 

Most commonly affected:

• Bolt-action precision rifles (6.5 Creedmoor, .308, .300 Win Mag) — high-velocity rounds mean more copper transfer
• Hunting and stalking rifles — where accuracy at distance matters
• Competition firearms — high round counts accelerate fouling 

 

Less frequently affected: 

• Rimfire rifles (most .22 LR bullets are lead, not jacketed) 
• Shotguns (unless firing copper-plated slugs) 

 

 

Why Choose a Dedicated Copper Remover 

Standard carbon cleaners won’t effectively remove copper. A dedicated copper remover chemically dissolves and lifts copper from your barrel without harming the steel beneath. 

The Bore Tech CU+2 Advantage 

• Ammonia-free formula — no harsh fumes or etching risk 
• Safe on all barrel types — stainless steel, chrome-moly, and coated barrels 
• Non-hazardous and biodegradable — safer for home workshops where ventilation may be limited 
• Odour-free — comfortable to use indoors in well-ventilated spaces such as sheds or garages 
• Professional-grade results — trusted by competition shooters and gunsmiths across the UK 

Unlike old-style ammonia-based solvents, CU+2 won’t damage your bore or release dangerous fumes, making it ideal for British shooters maintaining firearms in smaller indoor workspaces. 

 

Step-by-Step: How to Remove Copper Fouling (UK Guide) 

You’ll Need: 

• Bore Tech CU+2 Copper Remover 
• Bore Tech Proof-Positive Cleaning Rod — prevents bore damage 
• Bore Tech Jags & Patch Tips 
• Bore Tech Nylon Bore Brushes — ideal for copper removal to avoid false blue readings 
• Clean cotton patches 
• Nitrile gloves and a well-ventilated area 

Cleaning Process 

1. Safety First 
2. Unload and clear your firearm — always double-check the chamber and magazine. 
3. Initial Application 
4. Apply CU+2 to a clean patch and push it through the bore from chamber to muzzle using a Proof-Positive jag. For heavily fouled barrels, let it dwell for 10–15 minutes. 
5. Brush the Bore 
6. Use a nylon bore brush saturated with CU+2 and work it through the bore 10–15 times. The brush loosens embedded copper while the solvent dissolves it. 
7. Pro tip: Use nylon brushes with copper removers to avoid false blue readings from bronze brushes. 
8. Patch Until Clean 
9. Run clean patches through until they emerge white (blue or green patches indicate copper is still present). For stubborn fouling, repeat steps 2–4. 
10. Final Protection 
11. Finish with a light coat of Bore Tech Friction Guard XP Gun Oil to protect the bore from corrosion before storage. 

 

 

How Often Should You Clean for Copper 

Recommended intervals: 

• Precision / target rifles: Every 200–300 rounds, or when groups open up 
• Stalking and hunting rifles: After each season or extended use 
• Competition firearms: After each match day or 500+ rounds 

Copper removal isn’t needed after every range session — but regular maintenance keeps your rifle consistent, accurate, and reliable over thousands of rounds. 

 

 

Troubleshooting Common Issues 

Patches still show blue after multiple attempts? 

• Heavily fouled barrels may need overnight soaking (CU+2 is safe for extended contact). 
• Ensure you’re brushing adequately between applications. 
• Inspect the throat area just ahead of the chamber — carbon rings here often trap copper. 

New barrel break-in: 

During the first 20–50 rounds, clean for copper more frequently (every 5–10 rounds) to remove manufacturing residue and help establish a smooth bore surface. 

 

Keep Your Rifle Performing at Its Best 

Proper barrel maintenance is a cornerstone of responsible firearm care in the UK. Whether you shoot for sport, pest control, or deer management, removing copper fouling protects your investment and ensures consistent performance year-round. 

The Bore Tech range offers everything you need for professional-grade barrel care — from ammonia-free copper removers to precision cleaning rods engineered to protect your rifling. 

Shop the full Bore Tech cleaning and maintenance range now at Shooting Sports UK, including CU+2 Copper Remover, Proof-Positive rods, brushes, and Friction Guard oils — trusted by shooters across the UK for precision barrel care. 

 

 

Frequently Asked Questions 

What is copper fouling in a rifle barrel? 

Copper fouling occurs when microscopic particles from copper-jacketed bullets are deposited in the barrel’s rifling during firing. Over time, this build-up reduces accuracy and makes cleaning more difficult. 

How do I know if my barrel has copper fouling? 

Look for blue or green discolouration on cleaning patches, or notice your groups opening up at the range. These are clear signs copper removal is needed. 

Is Bore Tech CU+2 safe for all barrel types? 

Yes. CU+2 is completely safe for stainless steel, chrome-moly, and coated barrels. Its ammonia-free formula won’t etch or damage your bore. 

How long can I leave copper remover in my barrel? 

Unlike aggressive ammonia-based solvents, CU+2 can be safely left in the bore for extended periods, even overnight for stubborn fouling. 

Do I need to remove copper after every shooting session? 

No. For most shooters, copper removal every 200–300 rounds (or when accuracy drops) is sufficient. Over-cleaning can be counter-productive.