It’s a very new technology for a 600-year-old invention

(Online Editor's note: Be sure to check out these related stories: Getting the lead out and Eating lead: discarded bullets are endangering condors)

Think about this:

When the gunpowder in a cartridge – say a regular ol’ .30-06 – lights off, it instantaneously subjects the bullet to around 60,000 psi. The bullet slams forward into the barrel rifling, forcing it to spin at 187,000rpm, and by the time it exits the muzzle, the bullet is moving forward at a velocity of 2,600 feet per second. That’s roughly zero to 300mph in a couple of milliseconds. The bullet continues to spin madly all the way to the target, and the enormous centrifugal force is trying to throw the jacket off the bullet.

This illustration from the 1898 Appendix of Thierbach's 1895 Die Geschichtliche Entwickelung der Handfeurwaffen (The Historical Development of Hand Firearms) illustrates the transition from the paper-patched lead bullet (top) of 1883 to the “humane” full metal jacketed bullet (bottom) of 1887.

That’s asking a lot from a bullet, and it’s taken a hundred years of experimenting to get jacketed bullets to perform so well. Prior to that, bullets were made only of lead, sometimes hardened with a little bit of antimony. Jacketed bullets today represent a lot of engineering, some designed with the help of computers. Still, one aspect these modern marvels hasn’t changed at all in almost seven centuries: they’re made of lead. 

Wearing a jacket

As early as 1874 Europeans were experimenting with covering lead bullets in a hard metal jacket – not for hunting, but to ensure bullets would not  expand when they struck enemy soldiers (more about this later). After decades of R&D that saw bullet jackets made of steel, copper, nickel and various alloys, copper jackets became the standard. Hard enough to hold high velocity bullets together, copper is still soft enough to not wear out steel barrels too quickly.

For hunting purposes, manufacturers have been developing bullets to reliably expand at all reasonable ranges (velocities) on game animals of similar sizes. The result is a plethora of very specific bullets for specific types of game animals. Bullet jackets may be swaged to lead cores; they may be soldered together; molten lead may be poured into copper bullet jackets, all to make them hold together. For expansion, jackets may be thick at the base and taper away at the nose, they may expose the tip of the lead core, the tip may have a polymer plug to force bullet expansion on impact, or the bullet could simply have a hole in the nose of the jacket, a “hollow point” bullet. What they all have in common to withstand those enormous forces and still expand reliably is a copper jacket surrounding a lead core.

The exception has been large, heavy bullets intended for large, dangerous game like cape buffalo, elephants and the like. Such animals are so tough that bullets designed to expand instead come apart when striking them. Called “solids,” bullets for these animals are typically made of solid copper or bronze and are designed to not expand; instead, they are already of large enough diameter – up to a half inch or so – that expansion isn’t necessary. The guns that fire these big bullets have a punishing recoil that most hunters can’t claim to enjoy. And, except perhaps for grizzly bears and polar bears, solid bullets are universally banned for hunting in the U.S. – state laws require expanding bullets.

A lead-free future

Until recently, there’s never been a need (or market) for lead-free expanding hunting bullets. In researching and writing an article on specialty ammunition for a national magazine last year, I could find only one maker of such a bullet, Barnes, though I found several who make “frangible” non-lead bullets for law enforcement training. Frangible bullets atomize themselves to dust when striking steel training targets, and they are not at all suitable for hunting.

With increasing concerns about lead poisoning, both directly to humans and in the environment generally, there’s probably a coming day when lead will have disappeared from hunting bullets. If that seems unlikely, consider that there are still plenty of hunters around who remember the 1976 federal ban on lead shot for waterfowling. Many of them (including the NRA) fought against it, mostly because there was no suitable replacement for lead shot. The problem is that both shot and bullets need plenty of mass to retain downrange velocity and energy; projectiles made of lighter metals slow down sooner, which shortens their effective range and reduces their penetration. Projectiles also must be soft relative to steel so that they don’t damage barrels. It took lots of experimenting by manufacturers and teething pain for hunters, but today shotshells using bismuth instead of lead pellets for waterfowl are common, if more expensive, and the lead shot ban hardly gets mention anymore. The same may happen with hunting bullets, though it may take a bit longer. For competitive shooting sports, however, where we shoot thousands of rounds a year, lead alternatives are way too expensive besides being unnecessary.

‘Humane’ bullets?

Back to 1874: The development of jacketed bullets has its roots in concepts of “humaneness,” which is evidently contradictory when applied to humans and animals. In the Franco-Prussian war of 1871 each side accused the other of using “explosive bullets” intended to inflict ghastly wounds; the accusations prompted experimenters to fully enclose lead bullets in a hard metal jacket so that the lead would not deform or expand when striking a man – the “full metal jacket.” They found, incidentally, that a partial jacket, leaving the lead bullet nose exposed, would actually cause the bullet to expand on impact. By 1899 the Hague Convention had outlawed the “use of bullets which expand or flatten easily in the human body.”

So, state hunting laws today require expanding bullets because they are humane and international law prohibits them in warfare because they are inhumane. Put another way, bullets humane to shoot at people are inhumane to shoot at animals. It fits the strict definition of “humane,” but is ironic nonetheless.