There’s more to lead shot than you might think, explains Richard Atkins
Richard Atkins has decades of experience testing guns, cartridges and accessories, and is our expert on all aspects of ballistics, shotgun performance and technical analysis
Most of us don’t give much thought to those little round lead balls in our cartridges – but it’s those pellets that decide success or failure. Serious competition shooters understand the importance of using the right pellets for the job. Wads and velocity play their part, but ultimately it’s the shot which will determine what sort of patterns you are shooting, and how well you can break the targets – or not!
William Watt of Bristol is the man we have to thank most for the high quality shot we have today. Legend has it he was inspired by a dream where lead pellets ‘rained down’ from a church tower. He experimented with lead shot production, building a tower on his house and boring down into the ground below to gain more height of drop! This resulted in Watt taking out his patent, number1347, on 10 December, 1782.
Prior to Watt’s shot tower method, lead pellets had been produced by cutting sheets of lead into strips and then into cubes. These were rolled between heavy rotating discs, as one might mill flour from corn – a long, slow and arduous process.
Watt’s description detailing his new shot production process makes clear the failings of lead shot production prior to his invention: “A method of making small shot solid throughout, perfectly globular in form, and without the dimples, scratches and imperfections which other shot, heretofore manufactured, usually have on their surface.”
The drop system
In the ‘drop’ system, shot is produced by pouring molten lead through a perforated metal plate with hundreds of small holes drilled through it. The size of hole in the plate governs the size of lead shot that plate will produce. These holes are much smaller than the actual finished shot size because the lead forms droplets as it escapes through the holes, until a teardrop shape breaks free to fall into the cooling tank. On its downward journey the teardrop tail draws back into the pellet thanks to surface tension of the lead.
Watt also discovered the key to this process being able to make good, evenly sized shot. This lay in the preparation of the bed of filtering material built up several inches thick above the metal drop plate. This filter bed reduces pressure at the holes and spreads the molten lead evenly across the drop plate. Without this filter no pellets would be forme
