The science behind copper-coated lead shot
We speak to Eley Hawk, one of the UK's largest cartridge manufacturers, about the latest trend that is copper-coated lead shot.
Game Shots often have a preferred cartridge brand and load for various quarry – some are even die-hard loyalists who will buy them in huge quantities. As with many other pieces of kit, fads and fashions come and go. But is the latest trend of using copper-coated lead shot here to stay?
The technology has been around for many years now; the first examples of coated shot (with copper, nickel and even gold) date back to the 1950s. So why are copper-coated shot cartridges now in vogue?
If you take a look at online forums, people’s views surrounding the technology vary. You will find two distinct camps: those who are big fans of ‘copper cartridges’; and those who remain sceptical. The latter share a good point: “a shot in the right place will bring down any bird, regardless of the cartridge”, whilst the aficionados claim they are the hardest-hitting cartridge they have tried, and their shot to kill ratio has increased noticeably since they starting using them.
Indeed, neither camp delivers sound proof, so David Thompson, marketing manager for Eley Hawk, a brand that has worked with copper-coated shot since 1992, provided some more detailed information.
Eley's first cartridge to incorporate copper-coated lead was the Classic Game paper case – designed for use in traditional side-by-sides – and their latest is the Eley Zenith, a range released in 2015 to suit modern over-unders.
“Our engineers realised that the key to creating consistent shot patterns at range lies in ensuring that individual pellets can fly as straight as possible,” says David. “To achieve this they tried various things, but the one test which proved most efficient whilst remaining affordable was applying a thin coat of copper to the lead shot.”
As the element is much harder and smoother than lead, a coating of copper around the softer lead shot is said to reduce the friction between the shot and the barrel walls, therefore minimising premature deformation, yet remaining malleable enough at a typical range to transfer sufficient energy into a bird’s tissue and organs to kill it humanely.
Adding copper plating is a relatively simple process, and takes place once all normal stages of creating lead shot have been completed. The lead shot is bathed in a special ionic solution – a bath of dissolved copper in water and chemicals – which is then exposed to a direct electronic current. With voltage applied, the copper particles act as an anode (positive terminal) and the lead a cathode (negative terminal), thus the copper is attracted to the lead and sticks firmly and, hopefully, seamlessly to it.
The length of exposure and strength of electricity in this process is crucial. “For example, too much time in the solution will overcoat the lead and make it overly large and heavy,” says David, “and too high a voltage will cause hydrogen bubbles in the solution and lead to imperfections in the lead and overall finish.”
Having 'improved' the quality and characteristics of the shot, it would also make sense that the other components that make up a cartridge should be developed, too. “The powders we use are of the highest quality possible, to ensure that the burn is clean and consistent, and prevents balling of the shot,” admits David. “And we also use bespoke fibre wads.”
Tailored for copper shot, these wads are made of a higher density fibre to that used in standard cartridges, which adds further integrity under firing and prevents the now harder shot embedding into the wad – thus, adding even more consistency.
To bear in mind
In the current market, copper-coated shot sits at around six per cent more expensive than premium lead shot. “We have tested our Zenith cartridges against our premium lead loads on pattern plates out to 15–20 yards – using the same gun, chokes and barrels – and have found that the Zeniths have approximately 40 per cent more pellets within a 30inch circle. The general industry-wide consensus is that within the circle there should be no less than 120 pellets, with the copper coated product the average is 172. So, if you really think about it, you are getting a lot more shot for your money,” says David.
At the end of the day, regardless of the technology, no cartridge will make you a better Shot. Shoot what you are confident with and know that if you put it in the right place, the bird will be killed quickly and efficiently. And if you are still curious, why not experiment a little at the pattern plate with a few different cartridges and investigate the matter yourself?
CLICK HERE for more about Eley Hawk.