The Copper-Bullet Debate

By: Warren Gray

Copyright © 2020

“Using solid-copper bullets requires a different way of thinking than with jacketed, lead-core bullets...the use of lighter bullets requires ‘thinking faster’ instead of heavier.”

— Cutting-Edge Bullets’ web site, 2020.

Lead versus copper: That’s the great, bullet debate, which has recently been highly politicized, pitting science against industry, reason against emotion, and hunters against anti-gunners, with opposing sides often taking extremist views, and deliberate misinformation being spread like wildfire. This is as hot a topic as climate change, and nearly as divisive. So, let’s attempt to cut through the smoke and mirrors of both sides, and take a reasonable, rational, educated approach to this sensitive issue.

Examining it purely objectively, from a scientific point of view, people have known for thousands of years, at least since Greek and Roman times, that lead is a toxic substance, and detailed studies in recent years have proven this beyond all doubt. As one recent study clearly states, “The toxicity of lead is well-studied, and has been associated with myocardial infarction (heart attack) and stroke mortality, decreased brain volume, and even elevated crime levels.

“Children are especially vulnerable to lead poisoning, which results in intellectual impairment and reduced growth. The removal of lead from gasoline and house paint (also plumbing) has greatly reduced overall lead intake, and the remaining sources of lead intoxication are receiving more attention.”

Lead ammunition has posed a significant problem for large birds of prey, which feed upon the animal entrails left in the field by hunters. This has been the principal source of lead poisoning for the endangered, California condor, and similar problems affect the great bald eagle (particularly susceptible), golden eagles, turkey vultures, and white-tailed, sea eagles. In a similar manner, human beings may develop lead poisoning from the meat of wild game harvested by hunters.

The source of this lead ingestion, in both people and animals, is not the lead bullets themselves, but the fragmentation inherent in high-velocity, lead-core ammunition. It’s an irrefutable, scientific fact that lead ammunition is prone to fragmentation, sometimes into literally hundreds of tiny, even microscopic pieces, often losing up to 40 percent of their mass in tiny fragments that can stray up to 18 inches from the wound channel. So, there’s really no room for debate on the toxicity of lead particles. The true question is: What can we, and should we, realistically do about it?

American manufacturing industries have already taken significant steps. The last, primary, lead-smelting plant in the nation was closed in 2013, leaving ammunition companies with the sole option of using recycled lead, primarily recovered from the lead-acid batteries still used in automobiles, and virtually all major, ammunition manufacturers now offer non-lead, ammunition choices.

Since humans and animals do not ingest the actual, lead bullets themselves, but mainly the tiny fragments, our primary concern here is with fragmenting, high-velocity, hunting ammunition typically used to harvest deer and other wild game. There have been abundant studies to show that the average, “fragmentation threshold” occurs at an impact velocity (notmuzzle velocity) of approximately 2,260 feet per second, or Mach 2.0, which is the certainly the case for most centerfire rifles. Above that limit, fragmentation is very likely, and below it, fragmentation is rare.

Hunting bullets must expand, or mushroom, in order to create sufficient tissue damage over a broader cross-sectional area to assure a quick, clean kill, which is what all responsible hunters truly desire. Extensive testing of high-velocity, lead and copper bullets in ballistic gelatin, modeling clay, glycerin soap, and thousands of actual, wild game clearly demonstrates that the wound channels are approximately equal in size and overall depth of penetration, barrel life is essentially the same, and accuracy with modern, copper bullets is just as good as with a lead-core bullets, so these are not significant, differentiating factors.

Where the real difference comes into play is in the specific density, or weight, of each element. A one-cubic-centimeter (picture a 10mm cube) block of lead weighs 176 grains, whereas exactly the same-sized block of copper weighs only 139 grains, meaning that copper is 26.6-percent lighter than lead, given the same dimensions. So, for a typical, 150-grain, lead-core, hunting bullet in .30-06 caliber, a comparably-sized, copper bullet weighs only 110 grains.

In order to generate the same amount of kinetic energy to provide adequate takedown power in large animals, a lighter bullet must be driven to higher velocity. If we increase the copper bullet weight to a full 150 grains, it will be about 26.6-percent longer, taking up more space inside the cartridge casing, and therefore reducing the gunpowder capacity, and bullet velocity. This can be compensated for, however, by switching to a smaller-grained, faster-burning powder, which takes up less space inside the brass casing.

Since copper normally does not fragment, it retains 95 to 100-percent of its original, bullet weight, often penetrating deeper than a lead bullet, which sheds up to 40 percent of its weight through fragmentation, although this is reduced to 25 percent in premium, bonded, lead bullets.

On the Mohs Scale of Hardness for Metals, lead is rated 1.5, while copper (or brass, for that matter) is literally twice as hard, at 3.0. The extreme, hydraulic forces of impacting an animal’s body at high velocity, however, cause them both to expand in a very similar manner, yet copper, because it is harder, normally does not fragment, at least no greater than five percent. This weight retention means more weight and kinetic energy driving the bullet through the animal, so penetration will be deeper than lead under nearly all circumstances.

In the past, we have used larger and heavier, lead bullets when deeper penetration was desired, for example, switching to 165, 180, or even 220 grains in a .30-06. Now, recall that the original, design-specification, bullet weight for a .30-06, which is capable of taking almost any North American game, was 150 grains, later refined to 152 grains in 1938, so all wartime service in World Wars One and Two, and the Korean War, was at these bullet weights. Hundreds of thousands of enemy troops were shot with the .30-06 round, which was usually quite effective with just one bullet.

In my state, the nine whitetail deer that I’ve taken over the past five years all weighed between 75 pounds and 145 pounds, with about 110-115 pounds being the average for a buck, so they’re certainly no larger in the chest cavity than a small-framed man, meaning that a 150-grain bullet is usually quite sufficient for the task. But, I’ve seen hunters using larger and heavier bullets, when this is not really necessary.

A solid-copper bullet at 150 grains will penetrate more like a heavy, 190-grain, lead bullet, because it does not shed weight through fragmentation, so even these very-lightest, copper bullets may be prone to overpenetration, because too much weight at any given point inside the animal’s body means too much momentum.

Nathan Foster, the owner of Terminal Ballistics Research, writes that, “The current, copper bullets that are being pushed by various environmental organizations cannot achieve this type of wounding (weight-shedding through fragmentation.) These bullets do not shed weight...(and) if the hunter does not strike the animal perfectly, or does not have very high impact velocities on his side, there is a high risk of slow killing.”

Lawrence G. Keane, senior vice president of the National Shooting Sports Foundation (NSSF), stated that, “It’s actually the animals that groups supporting a (lead-ammunition) ban purport to want to help that would be the ones who suffer most.”

This is precisely why Cutting-Edge Bullets, which manufactures new, state-of-the-art, solid-copper bullets, clearly says on their web site that, “Using solid-copper bullets requires a different way of thinking than with jacketed, lead-core bullets...the use of lighter bullets requires ‘thinking faster’ instead of heavier.”

When using copper bullets, we must rethink the entire, bullet-weight formula that we used in the past, because the same effect of deeper penetration is now achieved simply by switching from lead to copper bullets, without increasing the weight. In fact, the best performance will come from a copper bullet of exactly the same external dimensions as a lead bullet, but it will be 26.6-percent lighter, and correspondingly faster. Writer Clint Wirick put it this way: “With this said, you can step down in bullet weight, and still see penetration as good or even exceeding lead-core bullets. Being able to step down in bullet weight might help alleviate some of the issues ballistically, as well.”

Now, with all of this background information in mind, let’s completely set aside politics (I know, that’s heresy in an election year, right?), federal and state laws, and bumbling bureaucrats everywhere, and examine this touchy issue strictly in terms of reasonable practicality, and shooter/hunter responsibility. Okay, so lead is bad and copper is better, for both humans and animals. We all understand that.

Hunting in general, and deer hunting specifically, is typically broken down into three separate “seasons” in most states: There is an archery season (I use a crossbow), which does not apply to this discussion, since only stainless-steel, broadhead tips are used (one eight-point buck already taken with a crossbow this season), and there is no lead or copper involved. Then, there is a black-powder, or muzzleloader, season, but since low-powered, black-powder bullets almost never reach the “fragmentation threshold” of 2,260 fps, this is not a major concern, as the bullets will not usually fragment.

I currently use lead-core, PowerBelt Aerolite bullets in my muzzleloader, because they are easier to load than plastic-sabot rounds, are a full .50-caliber in width, and have a ballistic tip for better aerodynamics, flatter shooting, and slightly longer range. With that being said, I shot one deer with a solid-copper, Barnes MZ Expander, hollowpoint bullet, and it only ran about seven yards, and was dead within just a few seconds. Solely for environmental concerns, however, I’ve already ordered some 250-grain (lightest-available weight), Thor Lightning solid-copper, ballistic-tip bullets (using the famous, Barnes X-bullet) in .503-caliber for use in the very near future.

Likewise, hunting with lead, shotgun slugs poses less of a health hazard, because the velocities are slow enough that fragmentation usually does not occur.

The third hunting “season” is the ever-popular, rifle season, which lasts about two and a half weeks in my state. This is when my Remington 700 in .30-06 comes into action, and I’ve been using premium, bonded, Remington Premier Scirocco, lead-core bullets in 150 grains until now, mainly because they are very-high-quality, extremely accurate, and they typically expand to twice their original diameter, when the industry standard, the norm, is currently 1.5 times the original diameter. But, like all high-velocity, lead ammunition, it is still prone to approximately 25-percent fragmentation of tiny, lead particles, which is a very-valid, environmental and human-safety concern.

So, once I’ve finished shooting my very last box of fairly-expensive, Remington Premier Sciroccos, I’ll be switching to Winchester Deer Season XP Copper Impact ammunition in 150-grains (note the light weight), which I’ve already purchased. The Winchester web site calls this, “A product engineered specifically for deer hunters. The Extreme Point, copper-solid bullet features an oversized, impact diameter...(for) more impact trauma, better energy transfer, and large wound cavities for faster knockdown.” It certainly appears to be very well-designed. Also, this new product is made in six different calibers, but they all use lightweight bullets, so Winchester has already done their homework on copper-bullet engineering and performance.

Nathan Robinson of Winchester said that, “It (Deer Season XP Copper Impact) has performed excellently by...putting deer down faster than ever. The same great, rapid expansion...but the copper bullet is tougher and penetrates farther.”

Not to be outdone, Remington has recently introduced their Premier HTP Copper Solid ammunition line, using the proven, Barnes TSX bullet, which expands to double its original diameter, in 15 different calibers, but using heavier bullets (168 grains for .308, .30-06, and .300 Win. Mag.) may result in overpenetration of wild game, and slower kills, since 168 grains of copper is equivalent to 213 grains of lead when it comes to penetration levels. I won’t be using these loads.

When it comes to military, police, and civilian self-defense ammunition, the primary concerns are from microscopic, lead-powder ingestion at shooting ranges, and from lead contamination in the soil at ranges and informal, practice areas. The U.S. Department of Defense has fully converted its war-reserve, 5.56mm M4 carbine ammunition to lead-free (including the M855A1 Enhanced Performance Round [EPR], a 62-grain, copper-core projectile with a 19-grain, hardened, steel tip, introduced in 2010), but their training rounds are still a mixture of lead-core and lead-free. The FBI and most police departments continue to use only lead-core bullets for training.

Some manufacturers offer solid-copper bullets in 5.56mm or .223-caliber, and these do not fragment, but instead, do their damage either through rapid expansion in a hollowpoint, or though tumbling in a solid-nosed bullet. This tumbling effect is more pronounced in a longer, heavier round, so 75 to 79-grain bullets are preferred, and long, 5.56mm rounds have been produced in either solid-copper or solid-brass.

Caracal Light Ammunition (CLA) of Abu Dhabi, United Arab Emirates (UAE), suppliers of ammunition to the French armed forces and other nations, produces a solid-brass, 79-grain bullet in 5.56mm at 2,722 feet per second, and a “high-performance,” solid-copper, spire-point, 95-grain bullet in 9mm at a blazing 1,485 feet per second!

This brings us to the topic of solid-copper, self-defense ammunition. For self-defense rifles, lead bullet fragmentation actually aids stopping power, preventing overpenetration, so copper bullets may not necessarily be the best choice here. Regarding pistol bullets, velocity is slow enough that fragmentation is usually not a factor, so it all comes down to which type is best for your handgun, and which has better stopping power, and the results for solid-copper ammo may be just as mixed as for lead-core ammo.

For example, last year, I tested a variety of 9mm loads from a compact, Ruger LC9s pistol, in both lead and copper, in wet, modeling clay, to simulate the terminal, ballistic effects of a possible, self-defense encounter. The results were surprising:

The Federal HST Micro lead-core, jacketed hollowpoint (JHP), at 150 grains, is a very-popular, slow and heavy, defensive round, which performed well in clay, but in ballistic gelatin, it overpenetrated, at 17.3 inches, which was probably to be expected, given its weight and momentum. The Defender Ammunition 124-grain, JHP round, also lead-core, performed well, but penetrated to 16.5 inches, which is enough to pass completely through a human chest cavity, again risking overpenetration.

Then, I tested three different, solid-copper, hollowpoint (SCHP) rounds for comparison. The super-lightweight, ultra-speedy, CorBon DPX 95-grain SCHP, at a very hot 1,300 feet per second, surprisingly proved to be a little too fast, shedding all six of its tiny, hollowpoint petals upon rapid expansion, and then the core continued onward, penetrating a full 15.2 inches (a bit too far), with only a .373-caliber base remaining. This was very disappointing for such a promising, hot load.

The Barnes TAC-XPD SCHP, at 115 grains, was much better, penetrating an ideal 12.3 inches, and expanding to .707-caliber, with a nine-inch-long, wound cavity that was 3.2 inches wide. Very impressive!

But the most-amazing of all was the brand-new, Norma MHP (Monolithic HollowPoint) SCHP at 108 grains, penetrating an acceptable (per the FBI) 9.5 inches deep (10.5 inches in ballistic gelatin), with a four-inch-wide, temporary cavity, and expanding to an incredible .937-caliber! (Yes, you read that correctly; nearly an inch wide!) This all-copper round is advertised as “the most-expanding, 9mm bullet in the world,” and it’s definitely not hype. Its spectacular, temporary wound cavity was about the size of both of my fists (from the wrist bones forward) touching each other. Truly astounding! So, needless to say, this is clearly my new, 9mm, self-defense load.

In .45 ACP, I use the Federal HST +P lead-core round in 230 grains as my primary load, because my son’s police department issues it as standard ammunition, and because it currently has the highest, relative stopping power of any .45 ACP cartridge, with one-shot stops in the 96 to 97-percent range, 14.9 inches of penetration, and expansion to about .91-caliber, or sometimes more.

I also have some CorBon DPX and Barnes TAC-XPD solid-copper hollowpoints available in 185 grains, but these don’t come close to the sheer, incapacitation power of the lead-core, HST round yet, so SCHP manufacturers have some additional work to do to win us over when our lives are at stake. But, if Norma made their amazing MHP in .45 ACP (only 9mm and .380 so far), I’d definitely buy it!

There’s still much to be done before the public widely accepts solid-copper bullets. It doesn’t help that the ammunition industry currently produces 90-percent lead-core bullets, and only 10-percent copper bullets, and solid-copper ammo costs on average 25 to 30-percent more, due to its hardness and higher melting point requiring additional energy and tooling requirements.

Yes, it’s definitely preferable to use copper bullets for hunting, currently the principal area of concern, and even for self-defense purposes, for a huge variety of very valid reasons, but there needs to be an industry-wide and nationwide change in thinking about the use of copper bullets before they become the desired norm, rather than the misunderstood, “copper-headed” stepchild of the shooting world.

Warren Gray is a retired, U.S. Air Force intelligence officer with experience in joint special operations and counterterrorism, and is an NRA member. He served in Europe and the Middle East, earned Air Force and Navy parachutist wings, and four college degrees, including a Master of Aeronautical Science degree, and was a distinguished graduate of the Air Force Intelligence Operations Specialist Course, and the USAF Combat Targeting School. He is currently a published author and historian. You may visit his web site at:

Photo Courtesy of Barnes Bullets.

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