Ammunition choice will depend on the gun you are using and the quarry. Some guns are not suitable for steel ammunition be it through age, material or choke restriction. Bismuth or Tungsten would be the best recommendation.
Standard steel ammunition may be shot through a non-steel proofed gun but there are only a few standard steel loads available. Click here to read guidance and fact sheets from BASC’s firearms team.
High performance steel ammunition can be shot through steel proof shotguns. You can find this by looking for the “fleur-de-lys” proof marks or its barrel markings that state the barrels are steel shot proof.
Steel ammunition has improved massively over the last decade and ballistically it has proved itself more than capable for the job. Remember the rule of thumb about upping the size of the pellets by two to allow for the pellet density difference between steel and lead.
You should always pick the cartridge to suit the quarry i.e. shot size three or four for duck and three, two, or one BB for geese. Wherever possible always choose a biodegradable wad.