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Will my shotgun be safe with steel shot cartridges?

With all the discussion about a move away from lead shot in the next five years, here are the answers to questions about steel loads

Q: How do I know if I can use steel shot in my shotgun? 

steel shot proof mark on gun

High-performance steel shot cartridges should only be used in shotguns that have passed the special steel shot proof and bear 
the words “steel shot” and a fleur 
de lys proof mark.

A: Check the barrel of your gun. The gun will be stamped ‘steel shot’ and have a fleur de lys proof mark.

This shows it will handle high performance steel. These cartridges should only be used in shotguns that have passed the special steel shot proof and bear 
the words “steel shot” and a fleur 
de lys proof mark.

However Simon Reinhold, gun trade consultant and shooting coach points out: “It’s important to note that guns made & proved outside the UK (the majority these days) may not have the words ‘steel shot’ in conjunction with a fleur de lys. My brand new Japanese-made Browning has CIP over fleur de lys – no words at all and it is proved for steel.”

High performance steel vs standard steel

Guns who have shot the odd standard steel load (most guns ‘Nitro’ proved to at least 930 bar will comfortably handle standard steel loads) may fail to realise that the box of cartridges they have just purchased are in fact high performance steel.

The latter should only be fired through guns that have passed steel shot proof and have been proved to at least 1,320 bar.

fleur de lys mark

The all-important fleur de lys mark that shows your gun is safe for steel

Yildiz Wildfowler

Barrels on a Yildiz wildfowler proofed for modern steel

Q: I only shoot duck on rare occasions, but I recently bought some bismuth cartridges and was horrified by the price of them. Is it possible to shoot steel shot from an ordinary side-by-side shotgun?

A: It depends on the shotgun. 
A gun of modern manufacture with 70mm chambers and preferably no more than half choke should be perfectly safe to use with standard steel cartridges, provided that 
it is in proof and in sound order. Because steel is less dense than lead or bismuth, you should choose a shot size that is at least two sizes larger than that which you normally use. 
If you are in any doubt, then check with your gunsmith. If you have an older English side-by-side, however, 
I would not recommend using even the standard steel loads, as these could damage the barrel walls.

Q: I have recently started using steel shot for pigeon shooting. Only thing is, do I need to tell my game dealer the pigeon have been shot with steel? Could it cause a problem for him so far as processing is concerned?

A: ( Peter Theobald) As far as I am aware, there are no health and hygiene issues associated with steel shot in pigeon entering the food chain.

Some game processors already put warning notes on their products, advising care with spent pellets in the meat, but I doubt whether there is any need to specify those pellets may be made from steel.

Q: Is steel shot different to magnum proof? I ask because I have two Laurona 3in Magnum 12- bores and wonder if they are suitable for steel? Should I check with a gunsmith?

A:  Yes, there is a difference. Without seeing the guns I can’t tell exactly, but I believe your Lauronas would be proofed to 1,200 bars, which would mean they are safe with 3-inch magnum lead cartridges.

Steel proof is something different, and the mark includes a fleur de lis as described above.  On multi-choke guns the choke tubes should also be stamped as being suitable for steel shot.

In short, it is neither wise nor safe to shoot 3in steel magnums through a gun/ choke combination which is not proofed for such a load.

Q: How would I know if my gun has been damaged by steel? 

The damage may be subtle – a slight swelling of the barrels at the choke. Sometimes the gun’s owner is unaware there is a problem until this is pointed out.

For example, some owners assume their guns will handle steel because they was proofed for 2.3/4in magnum cartridges. However if the fixed chokes are too tight just one cartridge up each barrel was sufficient to cause bulging.”

Steel shot warning

Always read your ammunition packaging carefully


A wildfowler warns

Mike is an experienced foreshore wildfowler.  He warns: “I’m very wary about choke. I keep half choke in my Hatsan, and I’ve hidden the other chokes so I don’t use one by mistake,” he said.

“Anyway, you do not need more than half choke with steel because steel patterns tighter than lead, so you will not be under-choked.”

Mike adds:  “The trouble is that people don’t read the packaging on their cartridges. If you are going to use modern high performance steel you really need to check that your gun can handle it.

“Regardless of what some people say, I would never use more than half choke with high performance steel.”

Other steel shot warnings

Some older Winchester over and under guns may be stamped ‘Winchester Proof Steel’.

However, this refers to what the barrels are made of, not what can be stuffed up them.

One shooter bulged a barrel on his side-by-side whilst pigeon shooting using a ragbag of odds and ends of cartridges accumulated during the game shooting season. Lurking amongst the standard loads was a high performance steel load. Once he had spotted the bulge, a careful inspection of spent cartridge cases revealed the culprit.

An AYA damaged by steel shot

An AYA O/U damaged and shot ‘out of proof’ by steel shot.

Rules for steel shot use

  • Check for the Fleur de Lys proof mark
  • No more than half choke
  • If in doubt, use bismuth – in fact with a vintage gun, err on the safe side and always use bismuth and even then consider having tight chokes eased open by a gunsmith.
  • Always read the packaging on your cartridges
  • With removable chokes only use those clearly marked as suitable for steel.
  • Being an alloy of iron plus carbon, steel can rust.
  • People tell horror stories of older steel shot cartridges in which the contents have rusted or even fused into a solid slug! Modern steel shot is coated to prevent rusting so this should not be a problem, however it still makes sense to store your cartridges in a cool dry place.
steel shot damage

A muzzle section showing how a steel load has not only scored the barrels but split one of them at the choke.