Cartridges whit steel shot are mainly made for hunting in damp areas and for those places where the use of lead shot is forbidden by the law. B&P proposes a new series of cartridges with steel shot meeting entirely all hunting needs. These shot are built with select components that guarantee an optimum efficiency in any condition.   The steel shot weigh approximately 29% less than the lead shot and therefore have a smaller residual energy: if this difference is offset by using a steel shot with a diameter that is 12% larger than that of a lead shot and at a starting speed that is roughly 5% higher, an equivalent residual speed and therefore an equivalent energy are rached, but with an effect that leads to a greater concentration of the shot rose as a consenguence of the almost undeformability of the steel shot. As a matter of fact the steel shot has a considerably greater hardness than the lead shot. This is so much so that it is almos undeformable in the firing stroke.   The lightness and the low deformability of the steel shot have made it necessary to build wads that have on the one hand the greatest possible capacity and that are able on the other hand to ensure the utmost protection by avoiding any contact between the shot and the shotgun barrel. Thanks to the special plastic material they are made up of, B&P wads are able to guarantee the total protection of the barrels up to -20' C.   The need to recover space inside the cartridge entails the use of container wads without shock-absorbing springing and the use of propelling powders whose sparkling combustion is suitable for this type of charging.