Projectiles made from copper alloys are remarkably capable for hunting and personal defense
They were made of lead and in most cases would moderately deform on impact. As new cartridges were introduced, velocities increased.
And with that increase in velocity, soft lead bullets would not effectively engage the rifling inside the barrel of the handgun.
To get around this, other materials like antimony, silver, and tin, were added to the lead to make it harder.
These ‘hardcast’ bullets were also mono-metal bullets but they were also too hard to deform on impact.
Need for Expansion
Those who were shooting living creatures wanted bullets to deform/expand, because bullets that do so make larger holes.
And larger holes mean more tissue destruction and hemorrhaging. To make this possible, bullet engineers began to create bullets with jackets that surrounded the soft lead core.
These jackets were made of materials harder than lead, like copper, gilding metal, and even aluminum.
These were not mono-metal bullets because the core was made of one material and the jacket was made of another.
Development of Bonded Bullets
Up until about 1990 the jacketed bullet with a lead or lead alloy core was the standard in centerfire handguns.
Bullet engineers learned how to manipulate the design, the strength of the jacket, and the hardness of the core, to essentially control deformation/expansion.
However, what they struggled with was keeping the bullet’s jacket attached to the bullet’s core during penetration, especially after impacting intermediate barriers or bone.
If the core and jacket separated, penetration often suffered. This led to manufacturers bonding the core and jacket so they would stay together after impact.
However, this is expensive and adds steps to the manufacturing process.
Modern Monolithic Bullets
About this time Barnes, which had been manufacturing copper mono-metal rifle bullets, also began making copper mono-metal bullets for handguns.
To initiate deformation/expansion these bullets had a large hollow point cavity that saturated tissues would enter when the bullet impacted living creatures.
By pre-stressing the circumference of the hollow point, bullet engineers could dictate the impact velocities that would make the bullet begin to open with petals that peeled back along the shank of the bullet much like a blooming flower.
Because these mono-metal bullets did not have a jacketed core, there was no jacket and core to separate.
This meant the bullets retained all their weight and penetration was deep and consistent.
Tweaking Mono-metal Bullet Expansion
The other appealing feature of mono-metal bullets for handguns is that they can be designed to open – deform/expand – over wider velocity ranges.
This meant that mono-metal handgun bullets were less sensitive to velocity variations, such as when they might be shot from a two-inch or six-inch barrel.
Mono-metal bullets also open immediately after impact and deform very consistently.
All this makes them ideal for not only self-defense handguns but for hunting handguns too.
Barnes is not the only company making mono-metal handgun bullets. Norma has a new copper mono-metal bullet they offer in their defensive handgun ammunition.
The Norma MHP bullet opens with four petals instead of the six that are common with the Barnes bullet. They also open wider and the bullets penetrate a little less.
Several other manufacturers offer expanding all-copper mono-metal bullets that vary in the number of petals they have and how wide the bullets flower open.
Enter the HoneyBadger
Working with Lehigh Defense, Black Hills Ammunition created a radical, all-copper mono-metal bullet for their HoneyBadger line.
This bullet is a non-deforming solid copper bullet. What makes this mono-metal bullet different is that the front of the bullet is scalloped to increase wounding through tissue damage via fluid transfer.
Since the bullet does not deform, it penetrates very well.
Of course, you can still purchase or make your own handgun ammunition that’s loaded with plain old lead bullets.
Lead bullets are indeed mono-metal bullets. But in the ammunition vernacular of today, when the term “mono-metal” bullet is used, it most often refers to an all-copper bullet like the Barnes TAC-XP.
They’ve become very popular and are loaded by a variety of ammunition manufactures.