It's
all about
Copper!
and you thought it was...
all about Lead!
Copper is now an important
alternative to lead ammo
The use of lead in ammunition has a long and storied history. Lead has been known to be useful – and toxic – since the days of the Greeks and Romans. Cast lead shot was used by ancient Greeks and Romans in their slings, and they could send slingshot farther than archers could shoot arrows! The lead mines in Cartagena of southern Spain were exploited by Carthage (a powerful ancient Phoenician city-state on the North African coast that dominated Mediterranean trade) and later by the Romans. Combined, they left a legacy of over 10 million tons of slag and evidence of death and illness among the 40,000 men who worked the mines.
In the 16th – 18th century, lead balls became the standard ammunition for muskets and early firearms. Lead balls evolved into conical projectiles after the development of rifling – the spiral grooves in barrels that provide spin (and gyroscopic stability) to the projectiles. With the development of smokeless powder and higher velocities came lead fouling – the process where the edges of the bullets “melt off” and create deposits in the rifling, decreasing accuracy and increasing the chance of potentially dangerous obstruction of the barrel. Copper jackets (often a 95% copper, 5% zinc alloy called “gilding”) were developed to prevent lead fouling and are still in use today, and lead has remained the core component in most modern bullets due to its high density, low cost, and optimal deformation properties. Unfortunately, lead-based ammunition and fishing weights remain significant sources of lead in the environment, impacting wildlife and human health through the food chain worldwide.
In 2026, "Monolithic" is the hottest word in gun ammunition. It's shooting vernacular for bullets manufactured from a single, solid piece of metal, most commonly copper or a copper-zinc alloy (like brass). Until recently, solid copper bullets (or copper alloy) had a bad rap. This ammo was considered inferior to lead in ballistics and cost, and it was only used extensively in places like California, where lead bullets for all hunting had been banned in an attempt to save the highly endangered California Condor, as Condors were ingesting lead from entrails and carcasses. The last 10 years have seen tremendous improvements in copper ammo ballistics, design, and cost.
Barnes Tipped TSX Bullets
Advantages of Monolithic Copper | |
|---|---|
• Non-toxic | They can be used anywhere that shooting / hunting is allowed. No environmental contamination. Lead-free. |
• Superior weight retention | Retain almost 100% of their weight, resulting in deeper penetration, more consistent wound channels & better kill rates ("ethical kills") on large game. |
• Controlled, reliable expansion | Designed to "mushroom," with expanding "petals." This maximizes energy transfer and tissue damage and give predictable terminal performance. |
• Superior penetration | Especially through bone, muscle, & hide. Highly effective for large / dangerous game. |
• Reduced meat contamination | Non-toxic metal, lead-free, and almost no fragmentation of metal into surrounding meat. |
• Equivalent (or better) performance | Less dense than lead (lower BC), they are often longer in length, with designs (+ higher MV) that improve aerodynamics. This results in a flatter trajectory. |
• Less barrel fouling than lead | Longer barrel life and less cleaning time required. |
Disadvantages of Monolithic Copper | |
|---|---|
Potentially higher cost | Copper ammo typically costs $1.50+ more per box of 20 rounds. Typical ammo costs $12 - $40 per box, depending on brand/size. |
May require a higher twist rate | Copper is less dense than lead, thus copper bullets are longer, and longer bullets require faster twist rates to stabilize properly. |
Potential feeding problems | Monolithic copper bullets are longer than lead counterparts, potentially causing feeding issues in some rifles or magazines. |
The so-called "ballistic coefficients" of monolithic copper ammo are usually less than those of lead-based ammo, because of the density difference between lead (more dense) and copper (less dense). While a longer bullet can have a better BC, the added length of a copper bullet often means it cannot be stabilized by standard barrel twist rates. To achieve adequate expansion without fragmenting (since copper is harder), many copper bullets have different nose profiles (like large hollow points) or a high-strength, polymer tip made of polyoxymethylene. On impact, the plastic tip acts as a wedge, forcing the hollow point of the solid copper bullet to open into a classic mushroom shape and not fragment, which helps the bullet maintain near-total weight retention. The high weight retention results in better "terminal performance." Thus, despite the lower BC, copper bullets are often highly effective for hunting, even if they drop faster at extreme ranges. In a study of 146 elk kills, high-performance copper bullets (Barnes TTSX, LRX, Hornady CX) showed 97.2% weight retention (ref).
The "BC" has caused a lot of confusion with the introduction of copper ammo. BC is a measure of external ballistic performance, and it is used as an input to ballistics programs to predict bullet elevation drop and wind deflection. There are two different BC models, called G1 and G7. Note that many manufacturers still report the generally higher G1 BC numbers, rather than the more accurate G7 BC that is designed for modern bullet shapes. Most ballistics software now supports the G7 BC profile. If comparing ammo, it is important to make sure the same profile is being compared - i.e., G1 to G1 or G7 to G7. The G1 numbers are not constant with velocity, which can introduce significant errors in calculations of flight performance. The higher BC's obtained from the G1 model are reportedly sometimes used for marketing purposes to publish misleading performance data. YMMV!
Here are some popular brands of monolithic copper bullets. They are available in a large variety of calibers.
Ammo Brands | Description |
|---|---|
Remington Core-Lokt Copper | A lead-free version of the classic, with high weight retention. Uses a monolithic, all-copper bullet. It expands via a precision hollow point that helps the bullet transfer energy on game. Good expansion across a wide range of velocities / distances. |
Winchester COPPER IMPACT | Accelerated expansion during to lrge polymer tip, flat trajectory with high G6 BC, lethal on deer, elk, and other big game, supreme energy transfer.
|
Federal TROPHY COPPER | TROPHY COPPER A reliable, accurate factory load often used for big game like elk. |
Hornady Hornady CX | Hornady CX (Copper alloy eXpanding). A high-performance, monolithic, non-lead hunting bullet designed for deep penetration, high weight retention (up to 95%) and extended range. Has a Heat Shield® tip. Good for medium to large game. Fully California compliant. |
Barnes VOR-TX / TTSX | Often considered the industry standard, these tipped bullets provide excellent expansion and high ballistic coefficients for various ranges. |
What about shotgun shells? Waterfowl and upland game birds have traditionally been hunted by shotgun, initially using shells that propel 1 - 2 ounces (25 - 55g) of ~95% lead alloy. Small to medium sized game can be taken with larger shot (or slugs). Depending on size and intent, each shell might contain up to 9 large pellets or over 400 tiny pellets. The total amount of lead (roughtly 28g) in a shotgun shell far exceeds that in most handgun or rifle rounds (9mm bullet ~ 7.5 g).
Wildlife that mistake lead shotgun pellets for food or grit and ingest it suffer devastating effects. Ducks and geese, for example, deliberately swallow small bits of stone and gravel to help grind up food in their gizzards. When this grit contains lead, the result will be lead poisoning. Poisoned birds have severe neurologic injury and walk with drooping wings and can’t fly, and eventiually die. A nationwide ban on lead shot for hunting waterfowl (ducks, geese, and coots) in the United States was fully implemented by the U.S. Fish and Wildlife Service in 1991. While this federal regulation prohibits lead shot for hunting migratory waterfowl, the use of lead ammunition for hunting other game, such as upland birds, remains permissible in most parts of the country. Since the lead ban, waterfowlers have switched from lead shot to alternatives like steel, bismuth, or tungsten. This has had a very positive impact on waterfowl populations, as well as decreasing the likelihood of accidentally ingesting lead-contaminated game at the dinner table.
The switch to primarily steel shot was extremely controversial. It was marked by intense hunter opposition, lawsuits, and claims that it ruined shotguns and caused high rates of crippled birds. Hunters complained that steel pellet shotshells were expensive, hard to find, and less effective, leading to "crippled birds" that died a few days later. Steel shot is lighter and less dense than lead, leading to reduced velocity and energy at distance. Despite the resistance, the switch was deemed necessary to prevent millions of ducks and geese from dying from lead poisoning annually, and steel shot has dominated the waterfowl ammo market. Although bismuth is more dense and showed promise as a better lead replacement than steel, pellets often fractured when shot, which resulted in poor shot patterns and reduced velocity at impact. The cost of bismuth has also skyrocketed since 2025, following Chinese export controls, as the U.S. is 100% reliant on imports for bismuth.
There has been renewed interest in copper for shotshell in the past several years, with dramatic improvements in ballistics. One name that stands out is BOSS SHOTSHELLS. Founded in 2018 by Michigan waterfowlers, BOSS Shotshells initially built its reputation by selling premium copper-plated bismuth, a non-toxic shot designed for waterfowl and upland hunting. The problem with pure bismuth was that the pellets often fractured when shot, resulting in relatively poor shot patterns. Copper-plating the bismuth resulted an a high-density, hardened, high-performance shotshell. The BOSS copper-plated bismuth shells are high density (closer to lead) and provide high-performance shot patterns for hunters and quickly became immensely popular, assisted by the BOSS hand-loaded quality, with direct-to-consumer sales to keep costs down.
In 2025, the price of bismuth skyrocketed due to tariffs and trade issues with China, the major world exporter of bismuth. This supply-chain crisis required a re-assessment by BOSS of their product line and future. BOSS did their research and decided to pursue a copper-only shot, dubbed CuProX, and the results were phenomenal. The copper shot performance was very similar to the bismuth in both the ballistics gel and pattern test. Copper could be sourced from US suppliers. The response by hunters was very enthusiastic, as the new shot "packed a punch!" Most important to BOSS, the new shot remained environmentally friendly.
CuProX is a next-generation, non-toxic, high-density copper shotshell technology. Its design improves aerodynamic efficiency and increases retained pellet energy by 18% at 40 yards compared with steel @1500 fps, and roughly 4–7% more than Bismuth. It features "TurbuFlow" technology to reduce drag, delivering dense, uniform patterns at long ranges and providing a cleaner alternative to bismuth. What started as a response to rising material costs became a catalyst for innovation. By engineering copper specifically for energy retention, flight stability, and consistency, BOSS didn’t just replace bismuth, they built a more advanced non-toxic shotshell in the process.
Hunters are an important conservation force in the U.S. and worldwide. Through the federal Duck Stamp, hunters help protect and restore habitat for migratory waterfowl and other birds and wildlife. The stamp, formally called the federal Migratory Bird Hunting and Conservation Stamp, is required as a license for waterfowl hunting. For every dollar spent on Duck Stamps, ninety-eight cents go directly to purchase vital habitat or acquire conservation easements within the National Wildlife Refuge System. Since 1934, almost 6 million acres of habitat have been conserved with the help of Duck Stamp funds. Through licensing fees, excise taxes on equipment, and donations to organizations, hunters contribute over $1 billion annually to conservation. They help manage population balance, prevent overpopulation, and protect habitat, forming a vital part of the North American wildlife conservation model. Hunting with non-toxic ammo helps to maintain this legacy.
Still not convinced about Copper ammo? Then check out these videos!
Video Title | Video Description |
|---|---|
Why Copper Bullets Beat Lead—No BS, Just Facts | #BallisticsBriefs | Explains why copper bullets outperform lead—in just 10 minutes. |
The Copper Bullet Myth Needs To Die (Real Results) | The Copper Bullet Myth Needs To Die |
What Happens When Copper Bullets Hit Ballistic Gel? (80,000 FPS) | Five popular copper bullets, a high-speed camera, gel blocks, & 2 guys seeking answers |
Ep. 225 - The SCIENCE of Copper Bullets | Hornady Manufacturing |
Lead vs Copper Ammo: It's time for a change. - Backfire | Backfire discusses the practical differences between lead and copper ammunition for hunting. |
Modern Sniper Copper vs. Lead | The Best Hunting Bullet | Modern Day Sniper to put copper, cup-and-core and bonded lead bullets vs. 2 types of ballistic gel |
Copper Versus Lead Core Bullets — How They Work | Excellent descriptions of the fundamentals. Nothing magical. Just metallurgy and physics. |
Myth-busting copper bullets - Fieldtester episode 1 | The most comprehensive test of copper bullets they can make, with as many rounds as they can. |
Firearms expert Andrew Venables puts copper bullets through their paces on range, showing how they win. | Andrew puts copper bullets through their paces on a range; they win on both accuracy and fillability. |
Conservation Media® - Making the Switch to Non-Lead Ammunition - National Park Service | How and why to switch from lead to copper - National Park Service's experience with feral pigs |