Using Steel Shot in older guns by Roger Hill

With the gradual shift from lead to steel shot, questions have been asked regarding the use of steel shot in older guns, especially old English guns.

As a liveryman with the Worshipful Company of Gunmakers, I have been able to ask David Miles, the Proof Master at the London Proof House, for clarification regarding the use of steel and super steel with older English guns.

The questions I asked and the replies from the Proof Master are set out below along with additional information regarding proof data.

My questions in italics:

 (RH) If an older gun has very good barrel wall thickness could steel and super steel be used through it?

(Ans) Under no circumstances should this be allowed to happen. The barrels might be thick enough, but the high pressures created by steel and super steel could still cause catastrophic failure at the breech. It must also be born in mind that many older guns could be quite tightly choked. How could this be ascertained without accurate measurement again causing the gun to fail, causing serious injury or even death.

 (Me) I recently overheard a coach talking to his Gun in the field saying it would be ok to use super steel on one of the higher drives as the gun looks in good order, with thick barrels. I checked the proof marks, ok for standard steel but it did look tightly choked so I strongly advised against this until the choking could be ascertained as the gentleman was not sure of the choke in the gun.

Better safe than sorry.

What would your view be on this and what would the consequences be if a person ignored the facts presented by the proof houses and used steel or super steel in a gun not proofed for the use of either type of steel, and it failed?

(Ans) The consequences could be very serious injury or even death.

When guns fail catastrophically especially at the breech, which of course has nothing to do with the thickness of the barrel walls, any number of outcomes could be the result.

Certainly, no unqualified person should give advice to others, with incorrect information as to what cartridges should be used in a particular gun. If in doubt, ask a qualified gunsmith.

If a loader/coach in their position of professional expertise and responsibility, were to give someone advice to use steel or super steel cartridges through a standard proof gun, especially an older gun, I wonder if someone with resulting injury could sue them.

Please do ensure all your gun users are aware.

(RH) What can the owner of an older gun in good condition do?

(Ans) If the gun does not have the correct proof marks for steel in can be submitted for reproof at either the London or Birmingham proof houses.

David Miles provided the following information regarding steel shot and proof pressures.

Standard proof 12g max service pressure 740 bar
Proof pressure min 930 bar

Superior lead 12g max service pressure 1050 bar
Proof pressure min 1320 bar

Superior steel same pressures as superior lead.
Service 1050 bar. Proof 1320 bar.

Can a superior lead proofed gun safely shoot superior steel cartridges (i.e. a 3 inch or 3.5 chambered gun)? David Miles said that superior steel cartridges can only be used in guns carrying the Fleur de Lys stamp as these guns have been proofed for steel shot at the higher pressures.

If superior steel is fired through a superior proofed gun not carrying the Fleur de Lys stamp a failure would not be covered under warranty. Furthermore, advising a client to the contrary could have serious legal consequences should a failure occur.