Give ‘Em The Bismuth

Bismuth shot has enjoyed a resurgence among hunters seeking better nontoxic performance and folks who want to shoot older guns. But although most understand the benefits of bismuth, the shot’s unique properties prompt some questions.

Introduced to the hunting market in the 1990s as an alternative to steel shot, bismuth—actually a bismuth-tin alloy—has a density of about 9.6 grams per cubic centimeter. That’s about 22 percent heavier than steel, which has a density of less than 8. For comparison, lead shot has a density of about 11. So obviously, bismuth pellets hit harder than steel pellets of comparable size. Further, because of the alloy’s malleable properties, bismuth is safe to use in older guns that steel shot might damage. Questions arise, however, when comparing bismuth to steel and lead—especially when considering the best shot size for various game birds.

General Rules

“To put it quite simply, what we recommend is if you’re used to shooting steel and want to make the change to bismuth, it’s like a two shot-size jump,” says Adam Moser, Federal’s director of product engineering. “If you’re used to shooting No. 2 steel for duck, you’d want to migrate to No. 4 shot to get that equivalent energy on target with bismuth.”

Federal’s bismuth loads—several 12- and 20-gauge HEVI-Bismuth offerings — reflect that. The loads are available with Nos. 3, 4 and 5 shot, which provide the same downrange energy as loads with Nos. 1, 2 and 3 steel shot, respectively.

The pellet equation seems simple enough, but bismuth shells actually provide even more benefits over steel. Because they use smaller shot, bismuth loads have much higher pellet counts than steel shells of comparable energy. That greatly improves pattern density and the number of hits on target. Further, Moser said those smaller pellets actually increase penetration.

“We focus on penetration energy, which is really the energy per surface area of the pellet,” he says. That is, if two pellets weigh the same but one is smaller, the smaller pellet will penetrate deeper because the energy is centered on a smaller surface area. So, No. 4 bismuth shot will actually provide equal or better penetration energy than No. 2 steel.

“Most people notice the difference,” says Federal’s shotshell product director Daniel Compton. “I did the first time I ever hunted with it. If the birds are at normal ranges, it’s like, ‘We’re just crushing them.’”

Beyond Speed

Many wing-shooters—especially waterfowl hunters—focus on muzzle velocity nowadays, as increasingly faster steel loads have improved performance and downrange energy through the years. Moser says speed is important with bismuth loads, but only to a point. There’s a balance of pattern efficiency and terminal performance to consider. Velocities common in hunting payloads today—1,350 to 1,450 fps—produce great patterns with bismuth, and because of bismuth’s increased density over steel, users also benefit from improved terminal performance. Pushing the material too fast might actually reduce a load’s effectiveness.

“If you start to get faster than about 1,500, you begin to see that point of diminishing returns,” he says. “At some level, bismuth has a factor of brittleness, too, and launching payloads too fast can make you lose some pellets to that brittleness.”

Improvements in technology have actually reduced the brittleness factor in bismuth-tin alloy, Moser adds, resulting in better performance and increased recognition from hunters.

“When bismuth was introduced, the price point might have been a bit too spendy for the waterfowl guy, and there were some inherent issues with pellet integrity,” he says. “The alloy maybe wasn’t as technical as it is today. Now, it’s more malleable and less brittle, and that’s solved most of those fracturing issues. I think that’s kind of what’s brought it back to the limelight. A new breed of hunters sees that.”