Density is the ratio of mass to volume. When you throw a baseball into a pool of water, the density of the ball is a big factor in how it sinks. In a similar way, the density of lead shot determines how much kinetic energy it transfers to a target during impact.
The density of a material is an important consideration when choosing a hunting or clay target load. It’s important to select the correct shot to suit your shooting style and specific bird species.
There are several alternatives to lead shot – steel, bismuth and tungsten-based shots – which all produce different effects on birds and are available in a variety of loadings and shotgun calibres. Simple patterning tests and practice on clays will give you a good idea of which shot is right for you.
Lead is the most common shot for upland game such as doves, pigeons, quail, woodcock and rail, but is not recommended for ducks and geese. There are some very effective non-lead options, but they require a significant increase in shot size for their effectiveness.
The density of lead shot is reduced by the space between the tiny spheres that make up the pellet. This free space makes lead pellets more susceptible to deformation in the barrel and reduces their effectiveness.