Things to Consider When Choosing Lead-Free Ammunition

The Fundamentals: Expansion and Energy Delivery

The fundamental principle of all hunting bullets is that the bullet must be slowed down upon impact to deliver its kinetic energy into the animal's body. This slowing down is achieved by the bullet expanding on impact – the diameter of the impact area becomes larger, increasing resistance, causing the bullet to decelerate and come to a stop or exit the animal at a significantly reduced velocity. A clear sign of this principle is the wound channel left behind, which would be very small with a full-metal jacket and considerably larger with a soft lead tip.

There is often confusion between kinetic energy and delivered energy, with the latter being the most important in a hunting context. Technically, a full-metal jacketed bullet and a soft-point bullet of the same weight, fired at the same velocity, will have the same kinetic energy. However, when they hit the target, they will deliver very different amounts of energy. Contrary to what many believe, the wound channel is not the primary reason the animal goes down. It's the hydrostatic shock and pressure drop resulting from the delivered kinetic energy in an animal body that is mostly made up of water. A large amount of energy delivered quickly creates a more significant hydrostatic shock than a bullet that doesn't expand but passes through the animal's body unimpeded.

So why is it essential to know this when transitioning to lead-free ammunition? The answer is that the expansion method suddenly differs from the principle upon which hunting bullets have been constructed for the past hundred years. This, in turn, changes the conditions for how and when the bullet performs at its best.

Velocity

This is perhaps the most critical factor to keep in mind. As a shooter, you often talk about the distance you're shooting and the performance of a specific hunting bullet at that distance. But at NORMA, we believe it is more important to discuss velocity – that is, how a bullet behaves at a specific speed.

The bullet always has the highest velocity when it leaves the muzzle. After that, it decelerates due to air resistance while simultaneously, under the influence of gravity, beginning to fall towards the ground. A hunting bullet needs a certain velocity to open up, but the difference is that a lead bullet, due to its softer material, will generally be more forgiving at lower speeds than a monolithic bullet that doesn't expand but merely deforms. Furthermore, these velocities will differ slightly depending on the caliber – generally, the larger the caliber, the more material needs to be deformed upon impact.

NORMA's ECOSTRIKE and EVOSTRIKE are loaded with a slightly higher velocity than comparable bullets and have a more streamlined design with a higher ballistic coefficient for reduced air resistance.

Penetration

Penetration can mainly mean two things: the bullet's ability to penetrate resistance before delivering its energy – because the animal is tougher than others – or its ability to handle hard parts like shoulder blades or ribs.

A soft bullet expands quickly and delivers a lot of energy early in the animal. Other bullets have slower expansion, giving the bullet the opportunity to penetrate deeper if there is more resistance. With a lead bullet, you can address this with different design solutions such as bonding, lead cores, or thicker jackets. In the case of ORYX, for example, you can achieve a bullet that opens quickly and easily while still holding together and retaining its weight, distributing the energy further into the animal or making it less sensitive to hard-part hits.

A monolithic lead-free bullet does not have the same opportunities to combine these properties. Either you make a bullet that opens easily at low speeds, or you create a bullet that opens more slowly and therefore penetrates better. The balance between them is not as easy to find since the bullet is cast in a single piece of metal, which reduces the expansion window somewhat.

ECOSTRIKE is built to guarantee good penetration both when hitting hard parts and delivering more in-depth energy. EVOSTRIKE, which breaks apart very early in the animal, is designed with a solid rear that continues through the animal and leaves a blood trail that is important for tracking. The various lead-free bullets on the market have more specific areas of use.

Deformation

The principle behind traditional lead bullets with soft tips is that the bullet expands upon impact, decelerates, and delivers its lethal kinetic energy into the animal's body instead of continuing unabated as a full-metal jacket bullet would.

A monolithic lead-free bullet works differently because it does not contain a softer core that expands its impact area when it decelerates. Instead, the bullet is pressed or machined from a single piece and designed to break apart or deform upon impact, creating a decelerating effect.

In general, this is not a revolutionary change – the principle for the lethal shot remains the same. However, changing the construction entails some differences worth keeping in mind when you start shooting lead-free.

ECOSTRIKE is a typical deformation bullet with a nickel-plated copper core that opens upon impact but retains its petals, leaving a clear mushroom shape with a broad diameter and 100% retained weight. In contrast, EVOSTRIKE fragments upon impact – the front half is made of tin with inner perforations, which causes the bullet to break apart with rapid and massive energy delivery as a result. ECOSTRIKE acts much like a bonded bullet, while EVOSTRIKE behaves like a wet bullet with high stopping power. Furthermore, ECOSTRIKE is loaded in a Silencer version with even higher velocity for maximum energy delivery.

Stabilization Distance

A detail that is often overlooked is that a bullet leaving the barrel is not perfectly aligned in the air as it might appear in a cartoon. To ensure stable flight, the bullet is set in rotation around its own axis using rifling in the barrel. As a result, the bullet exits in a slightly tilted or angled position in relation to the longitudinal direction, and it's not until further down the trajectory that it stabilizes in its orientation. The distance from the muzzle at which the bullet reaches a stable position mainly depends on its velocity, the barrel's twist rate, and the bullet's length and shape.

For example, a 7 mm Rem Mag BONDSTRIKE – a fast caliber with a long bullet and a pronounced ogival shape – won't have stabilized until around 80–100 meters along its trajectory. A hunting bullet is designed to perform optimally when encountering resistance head-on. Even here, lead would be more forgiving if the bullet strikes at a slight angle. A deforming bullet could theoretically have poorer expansion at short distances if the chosen bullet is long and very streamlined.

NORMA has aimed to strike a balance between bullet length and weight. In several cases, we have reduced bullet weight slightly to shorten the projectile's length, thus reducing the stabilization distance and making it more effective at shorter ranges. EVOSTRIKE has a somewhat stubbier design that makes it highly effective at very short distances, while ECOSTRIKE, with its more aerodynamic design, is a better choice for shots at larger game and longer distances.

Ricochet

A monolithic copper bullet is more prone to ricochet than a lead bullet, as lead bullets tend to expand and lose velocity upon impact. Bullet traps, backstops, and the surrounding environment are always important to monitor while hunting, but it's crucial to exercise even greater caution when marking new stands and selecting shot angles. Frozen ground, forest roads, and rocky terrain become extra hazardous when using monolithic copper bullets. Although safety should always be a top priority, there are reasons to incrementally increase safety margins in your planning as the use of harder bullets becomes more common.

Bullet Weight

Bullet weight is a factor in determining how much kinetic energy the projectile has upon impact – more kinetic energy translates to higher potential energy delivered to the target. However, with monolithic bullets, there is also more material to open up. It's generally important to be aware of both the distance and the stabilization distance.

For instance, a pointed standard bullet in 9.3x62 could theoretically behave like a full-metal jacket round at extremely close range, while it might act similarly at very long distances when the bullet has significantly slowed down. Since many lead-free materials are usually lighter than lead, it's also necessary to make the bullets longer to maintain impact energy. This, in turn, places higher demands on the stabilization distance and twist rate.

Barrel Wear

This is a hotly debated topic, and many believe that the harder, solid copper bullet wears down rifling and creates more fouling in the barrel. Theoretically, this might be true, but in tests, the barrel's condition does not appear to be significantly affected over time. The number of shots fired before wear becomes a problem is still high enough for the average hunter not to have to consider it.

However, a solid copper bullet might deposit slightly more fouling in the barrel than a copper-jacketed lead bullet. Copper deposits are difficult to remove, especially in a cold barrel. Regular cleaning for the sake of accuracy is therefore essential when shooting lead-free. Choosing a nickel-plated bullet like ECOSTRIKE or EVOSTRIKE can also reduce fouling inside the barrel with frequent use.

Twist Rate

The firearm's rifling rate can also affect the distance at which the bullet stabilizes. For monolithic bullets, it's more critical that the barrel's twist rate matches the bullet so that it acquires the proper rotation and can stabilize when it doesn't hit perfectly straight. Keep this in mind if you plan to significantly shorten the barrel.

Bullet Shape

This area intersects with stabilization distance. The majority of hunters take shots at distances between 30–100 meters, while a minority regularly hunt at ranges exceeding 300 meters. Considering that velocity is an important factor, the consequences of high retained velocity also include longer stabilization distances, during which hitting the target may theoretically reduce the monolithic bullet's ability to expand optimally.

To optimize the bullet's ability to maintain velocity, it must be made long and streamlined. A good Ballistic Coefficient (BC) helps retain speed even at long distances, but it also affects the distance at which the bullet is in an unstable position from the muzzle onward. Once again, lead bullets theoretically have a wider operational range compared to monolithic bullets.

Higher Demands on the Hunter

NORMA's monolithic copper bullets are designed to mimic the properties of lead bullets as closely as possible. However, there are slight differences, and in the long run, this places higher demands on the hunter and shooter than before. The so-called expansion window inevitably shrinks with a monolithic deformation bullet. It's bigger with premium ammunition than with cheaper variants, but still smaller than a corresponding lead bullet. This necessitates a higher level of awareness regarding distance, shot placement, environment, shooting angles, and – above all – the choice of ammunition.

At NORMA, we have developed our lead-free range to meet the high demands of hunters in terms of bullet construction, casing consistency in production, powder characteristics, and loading for each product and caliber. Now it's up to you.

Norma Product Manager Anton Brask shares his best tips on using lead-free ammunition for hunting, including choosing the right bullet for the right type of game, taking barrel length into consideration, optimizing hunting grounds and investing in good quality gun care products.

1. There is a tendency to overestimate the importance of impact energy which is dependent on bullet weight and velocity. Instead, focus on how the bullet delivers its energy into the game. Lead-free bullets are generally lighter and there is a risk that you only focus on grams and don’t think about how the bullet deforms or fragments on impact. Choose a bullet according to how ”bulletproof” the game you intend to hunt is. Easily killed game such as roe deer, fox and fallow deer need a bullet that delivers a lot of energy right on entry, for example a fragmenting bullet. Tougher game such as wild boar and moose need a bullet that delivers the energy further into the animal, for example a monolithic copper bullet that deforms on impact.
   
2. Take the length of the barrel into consideration. Velocity is lower in shorter barrels and speed is needed for lead-free ammunition to function optimally. Few weapons today are delivered with barrels up to 60 cm, which is the standard length for ammunition according to CIP. Furthermore, if you have had your stock barrel shortened, you can assume that the output speed is significantly lower than what is indicated on the box. To counter this use NORMA’s Silencer Series, which compensates for the velocity loss with more speed in the charge.
3. Adapt your hunting grounds for the use of lead-free ammunition. Review your hunting stands based on shot angles, ricochet risk and dense vegetation. Be prepared to move your stands, build elevated blinds and clear vegetation to ensure a safer hunt.
4. Invest in some really good gun care products. You will need a solvent for copper removal, a brush or BoreSnake for cleaning and oil to keep the rust at bay. Clean regularly to maintain rifle accuracy.
5. If you have been hunting with lead ammunition for a long time, you will most certainly discover some differences in ammunition performance. Document your shots and if possible, find and save the deformed projectiles. Make a short note in a notebook about the distance, as well as what happened when the game was hit. This way, you will be confident in how the ammunition performs, regardless of distance or type of game.