Steelproof markings on a shotgun in the UK indicate that the firearm has been tested and certified to safely handle steel shot, particularly high-performance steel shot. These markings are applied by accredited proof houses, such as the Birmingham Proof House or the London Proof House, to confirm the shotgun meets safety standards for the pressures and stresses associated with firing steel ammunition.

Common Steel Proof Markings in the UK

The fleur-de-lys, or lily flower, is the internationally recognized mark for shotguns tested for high-performance steel shot. Found on the barrel, near the proof marks or chamber area, it indicates the shotgun has passed rigorous tests for firing high-pressure steel cartridges.

Fleur-de-Lys Symbol:

The fleur-de-lys, or lily flower, is the internationally recognized mark for shotguns tested for high-performance steel shot. Found on the barrel, near the proof marks or chamber area.This indicates that the shotgun has passed rigorous tests for firing high-pressure steel cartridges.

Pressure Markings:

Steel-proofed shotguns are tested at significantly higher pressures than standard proofing for lead shots. Markings like 1320 bar or higher indicate the proof pressure for high-performance steel.

Chamber Length:

Steel shot often requires longer chambers, marked as 70mm (2 ¾"), 76mm (3"), or 89mm (3 ½"). This marking shows the maximum cartridge length the shotgun can safely accommodate.

CIP Markings:

Proofing is overseen by the Commission Internationale Permanente (CIP), a European organization governing firearm safety. CIP-approved proof houses stamp their marks to certify compliance.

Choke Markings:

Some shotguns include recommendations or warnings about choke suitability, such as: Avoiding full chokes with steel shot. Using modified or improved cylinder chokes for best performance and barrel safety.

Why Do UK Shotguns Need Steel Proofing?

The requirement for steel proofing is driven by environmental regulations, particularly the restrictions on lead shot over wetlands under the Environmental Protection Regulations. Steel shot is a widely accepted non-toxic alternative to lead, making steel-proofing essential for modern shotguns.

Environmental Regulations

• Banning Lead Shot: In the UK, the use of lead shot is restricted in certain areas, particularly:
  • Over wetlands, under the Environmental Protection (Restrictions on Use of Lead Shot) Regulations.
  • For waterfowl hunting, in compliance with international agreements like the AEWA (African-Eurasian Waterbird Agreement).
• Steel as an Alternative: Steel shot is a widely accepted non-toxic alternative to lead, making steel-proofing essential for modern shotguns.

Higher Stresses of Steel Shot

• Harder Material: Steel is less malleable than lead, meaning it doesn’t deform as much when fired. This increases pressure inside the barrel.
• Potential for Barrel Damage: Non-steel-proofed shotguns are more prone to damage, such as:
  • Scoring or scratching of the barrel.
  • Bulging or splitting, especially with tight chokes.
• Proofing Ensures Safety: Steel-proofing certifies that a shotgun can withstand these stresses without compromising performance or safety.

High-Performance Steel Loads

• Modern high-performance steel cartridges generate greater pressure than traditional lead or standard steel loads.
• Steel-proofed shotguns are tested to handle these pressures, ensuring safe use with high-performance ammunition.

Compliance and Liability

• Using steel shot in a non-steel-proofed shotgun can void warranties and raise liability issues in case of accidents.
• Proofing ensures manufacturers and users meet safety and legal standards.

Safety Considerations

Using steel shot in a non-steel-proofed shotgun can void warranties and raise liability issues. Steel is less malleable than lead, meaning it doesn't deform as much when fired, which increases pressure inside the barrel. Proper proofing ensures manufacturers and users meet safety and legal standards.

Consequences of Using Steel Shot in Non-Steel-Proofed Shotguns

1. Barrel Damage:
   • Steel shot can scratch or erode barrels not designed for its hardness.
   • Over-tight chokes (e.g., full chokes) can cause barrel bulging or deformation.
2. Reduced Longevity:
   • Non-steel-proofed shotguns may wear out faster with repeated use of steel shot.
3. Safety Hazards:
   • The increased pressure from high-performance steel loads can lead to barrel rupture, posing risks to the shooter and bystanders.
4. Legal Implications:
   • Using inappropriate ammunition may breach firearm safety laws or insurance conditions.

Exceptions: Do All UK Shotguns Need to Be Steel Proofed?

Not all shotguns in the UK need steel proofing, but it depends on how and where the shotgun is used:

• For Lead Shot Use: If you exclusively shoot lead shot in areas where it is permitted, steel proofing is unnecessary.
• For Steel Shot Use: Shotguns used for hunting waterfowl or shooting in areas where lead is restricted must be steel-proofed to ensure safety and compliance.

How to Ensure Your Shotgun Is Steel-Proofed

1. Look for Markings:
   • Check for the fleur-de-lys symbol, proof pressure in bars, and appropriate chamber length on the barrel.
2. Consult the Manufacturer:
   • Review the user manual or contact the manufacturer to confirm steel shot compatibility.
3. Seek Professional Inspection:
   • Have a gunsmith inspect your shotgun if you’re unsure of its proofing.
4. Consider Re-Proofing:
   • Older shotguns can be tested and re-proofed by proof houses to certify their suitability for steel shot.

Conclusion

Steel proof markings, such as the fleur-de-lys, ensure that a shotgun is certified to safely handle steel shot, particularly high-performance loads. While not all UK shotguns need to be steel-proofed, it is essential for those used in areas with lead shot restrictions or for waterfowl hunting. Understanding and verifying these markings ensures both safety and compliance with UK regulations, allowing you to enjoy shooting responsibly and effectively.