By using the interchangeable choke tubes that dominate the current crop of smoothbores, gunners can dial in their pattern for anything from close-range quail to a distant duck to a gobbler’s head at 25 yards. While the denotation on the choke tube is a guide, there are factors that can alter the percentage patterns it produces. The harder the shot, the tighter it will pattern. Copper, or nickel-plated shot will pattern tighter than an equivalent load of soft lead shot. Steel or tungsten/polymer shot will pattern even tighter. Larger shot sizes normally pattern more tightly than smaller sizes of the same shot hardness.