The exhaustively reviewed Texas Dove Lethality Study found the killing power of lead and steel shot was roughly equal – and this could be why, says BASC Council member Alasdair Mitchell, writing in his Sharpshooter column for Shooting Times.
Laboratory research does not always match real-world conditions. Sometimes, the disparity is due to a small yet significant factor that the researchers failed to include in their modelling. Something like this has just been revealed in the field of shotgun ballistics. A new piece of science has blown apart the myth that steel shot must be inferior to lead.
The fact that most shooters couldn’t tell the difference between an appropriate steel load and lead was shown in a huge piece of fieldwork carried out a few years ago in Texas (of which more later). But this more recent research suggests a reason why steel performs as well as lead in practice, despite the latter having greater density.
The new study was commissioned and funded by BASC, but conducted by a scrupulously independent ballistics expert at Cranfield University‘s defence and security department. It confirmed that lead pellets penetrated about 10% further into bare ballistic gelatine than upsized steel pellets. No surprise there. For game shooting, this penetration advantage is not decisive, because the adage that pattern fails before penetration holds true.
Within normal shotgun range, 10% less penetration may not be critical, providing the minimum threshold is met. Pattern is more likely to be key.
Yet the Cranfield study made an additional finding: the lead penetration advantage disappeared when the ballistic gelatine was encased in pheasant skin with feathers. Traditionally, shotgun pellet penetration tests are conducted by firing into blocks of bare ballistic gel. At Cranfield it was shown that where the pellets have to get past skin and feathers before entering the gel, steel shot two sizes larger than its lead equivalent penetrates just as far lead.
In some cases – such as the consistency of penetration right across the pattern – it does even better. And this is at ranges up to 50 yards. There is a suggestion that going up even one shot size might be effective, given a good-quality pattern.
Steel shot, being harder than lead, is much less likely to arrive on target in a deformed state, and seems to cut through feathers more readily. Feathers might seem like an insubstantial barrier, yet think of the effort of digging a spade into earth covered in matted grass compared with digging it into bare soil. How many times have you plucked a shot pheasant and seen bits of feather balled up around embedded pellets?
The Cranfield research may help explain the results of the biggest field test of steel and lead loads ever conducted. The Texas Dove Lethality Study was conducted over 2008 and 2009. The data went through an exhaustive review before being published in December 2014. Shooters selected by lottery fired more than 5,000 shots and more than 1,100 mourning doves were autopsied. Crucially, the shooters had no means of knowing whether they were using steel or lead.
And the results? In the correct size, steel worked just as well as lead. And now the Cranfield research may have shown why.