My first big-game experiences involved a .243 Winchester and cup-and-core lead bullets. Because it was the only centerfire rifle I owned, I used that rifle – and those lead-core bullets – to shoot everything from coyotes to bull elk.

That was 40-plus years ago.

Obviously, much has changed in the intervening decades regarding bullet construction and powder technology. One of the largest developments is the monolithic copper bullet. Randy Brooks, who purchased Barnes Bullets from its original owner, Fred Barnes, is credited with bringing the idea to fruition. The Barnes X Bullet hit the market in 1989 to mixed reviews. Early X Bullets were noted for producing high chamber pressures, introducing copper-fouling and frequently failing to expand adequately on lighter big game.

Barnes quickly corrected these issues, the Triple Shock bullet introduced “pressure-relief grooves” on the bearing surface, reducing pressure and fouling, and a modified hollowpoint cavity that initiated more reliable expansion. Polymer tips were later added, which seemed to promote even more reliable expansion. Barnes Bullets have become a favorite amongst serious big-game hunters, with a plethora of mono-copper bullets quickly following, including Hornady’s GMX (now the refined CX), Cutting Edge Bullets, Hammer Bullets, Quality Cartridge Game-StopR, and Badlands Precision, just as examples.  

This was inevitable. Copper is considered nontoxic (though it will kill trees). California started the trend with dubious no-lead “Condor Zones,” and eventually expanded to include the entire state. Some state and federal refuge lands followed suit. The fear of ingesting lead fragments steered still more hunters to copper bullets.

Love them or hate them, there are real advantages to the monolithic copper design – and some real disadvantages. The real con is copper is much lighter than lead, meaning a bullet weighing the same as a traditional lead-core slug, or even lighter, can require faster rifling twist for proper stabilization. Adequate rifling is just not available in many classic rifles, raising compatibility issues. Yet, that same long-for-weight dynamic can introduce excellent ballistic coefficients, granted enough rifling twist is available for stabilization. Pure or gilded copper is also consistent in makeup, and since copper bullets are milled instead of molded or stamped, they generally provide excellent consistency.

The largest selling point of monolithic designs is a high percentage of weight retention, which translates into reliability and deep penetration from a smaller, lower-weight bullet. I’ve seen figures, educated guesses I would call them, that say that adding 15 to 20 grains to the weight of a mono-copper bullet gives a shooter an idea of how it will compare to a lead-core slug’s terminal performance. For example, an 80-grain Barnes TSX BT would provide terminal performance comparable to a 100-grain Remington Core-Lokt. There is no empirical evidence this is true, but antidotal field evidence tells me it is. Given this stipulation, big-game hunters get flatter trajectory via lighter bullets that hit as hard and drive as deep as heavier lead slugs.

This makes the .243 Winchester a prime candidate for the copper-bullet treatment, turning a cartridge so many deem big-game marginal into a more lethal package. An 80-grain Barnes TTSX BT, for instance, becomes mule deer or caribou ready, a 90-grain Hornady CX suited to, say, elk duties with carefully placed shots.  

The .243 Winchester test rifle split the difference between traditional 1:10 rifling twist and the 1:7.5 twist of cartridges such as the 6mm Creedmoor. This was a “Kiwi-made” Hardy Rifle Hybrid distributed by Legacy Sports International, the same outfit supplying Japanese-made Howa rifles. The Hardy Rifle Hybrid includes a switch-barrel/bolt-head design that allows shooting many cartridges from a single rifle. Changing barrels requires less than a minute, a few more minutes required to swap bolt heads. Barrels are cutting-edge, carbon-wrap designs, the ergonomic stock is also 100 percent carbon fiber. The receiver is milled from 7075-grade aluminum. The proprietary spiral-lug head seats into a stainless steel extension of the carbon barrel to make this possible. Everything about the Hardy Rifle is state of the art and precision engineered. It has also proven a highly accurate test vehicle.

Five bullets were chosen for testing, covering the big-game hunter for everything from pronghorn and Coues’ whitetail to bull elk. These included Barnes’ 80-grain TTSX BT, Badland Precision’s 80-grain Bulldozer-2, Barnes’ 85-grain TSX BT, Hammer Bullets’ 88-grain Hammer Hunter and Hornady’s 90-grain CX.  

One stipulation often associated with mono-copper bullets is seating depth. Monolithic bullets can prove frustratingly finicky accuracy-wise. I once believed they just weren’t as inherently accurate as lead-core bullets, until I started seating them a touch deeper than traditional slugs – .010 inch off the lands instead of .005 inch, for instance. This jump into the lands, it is believed by many, helps better “seat” the harder copper into the rifling, providing a better seal and improved accuracy. I have no way of proving this, as it is by no means universal, but it works often enough that I generally follow this rule.