20G Game & Wetland Steel is available with 24grams of Steel shot in size 5. Plastic wad only. Standard Performance Steel.
24gms/5 (3mm) Standard Performance, Standard Nitro Proof Modern Shotgun. Half choke maximum
Standard Steel ammunition can be used in any shotgun (other than Damascus/twist barrelled guns), in good order bearing any London or Birmingham proof symbols 1954 onwards. For pre 1954 shotguns guidance will be needed from the British Proof Authority.
The shotgun must be chambered for the case lenght of the ammunition as a minimum. Longer chamber lengths can be used with shorter ammunition.