However, the fact that steel shot exerts much more stress on choke tubes has not changed. The problem is that steel shot is much harder than lead. It will transmit much more energy to the choke when it strikes the conical portion and if the tube is not of sufficient strength it will cause it to deform. This is known as “choke creep” Over a period of time choke creep can lock a choke in the barrel so that it is next to impossible to remove.