Deer bullets and how they work
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- Last updated: 26/09/2022
The bullet is the most important item you will use in your rifle, but get the choice wrong and the results will be less than perfect. There is a vast array of bullet types, all of which have a profound influence down range.
Matching the correct bullet to the type of game you intend to shoot is vital. Fail to do this and you run the risk of inadequate penetration, poor bullet expansion or too much expansion. You can spend a fortune on equipment and clothing, but when that bullet leaves the muzzle, you had better be sure it is capable of achieving humane, first-shot kills.
For all game species, a predictable, expanding bullet is necessary and a legal requirement in the case of deer species. Trouble is, not all expanding bullets perform the same, especially when it comes to some of the new lead-free options.
There is no magic bullet, but with careful thought, the correct type can be used to its best.
Deer bullets are different. Where a fox round is usually travelling very fast and needs to only penetrate softer body tissue, a rapidly expanding bullet is fine, but a deer round needs to penetrate deeper into the body cavity and then expand enough to cause lethal results. This is a tough order and a lot depends on the size of the deer shot and at what range you engage the beast. Here, the ability to reload can be enormously advantageous over factory loads, because you can use one bullet type for all deer but load the velocity accordingly to suit the species size. However, most factory loadings now offer a vast array of different bullets and speeds, so actually, they can be a better, fuss-free alternative.
When head or neck shooting, a fast, frangible bullet is desirable to instantly disrupt tissue, whereas the classic heart/ lung shot calls for a slower, expanding bullet that penetrates more deeply. Let’s look at some bullet designs.
The front section of the bullet is open with a void beneath, allowing the copper jacket to rupture and then allow the lead core to expand. How ‘hollow’ is dependent on application and manufacturer. Too hollow with a thin side wall means the bullet will expand too quickly. All major manufacturers make a hollow point of some description.
Conventional soft point bullets have the lead core exposed at the tip. This starts the bullet expansion and can have the form of either a flat, round or spitzer design, which will make a big difference down range, as the data will show. Again, most manufacturers make a soft nose as they are always dependable performers in a wide range of guns.
Nosler has designed a polymer-tipped bullet in both varmint (for rapidly expanding) and deer construction (for predictable expansion). The polymer tip, colour coded to match the calibre, resists deformation, retains Ballistic Coefficient (BC) in flight and starts the initial expansion on impact.
Hornady’s famous all-round vermin and fox bullet uses a polymer tip like the Ballistic Tip, which is designed to withstand hyper velocity rounds. When the tip comes into contact with the target, the thin jacketed wall and lead core expand very rapidly, thus causing maximum energy transfer and little risk of ricochets.
Sierra’s bullet is very similar to the V-max projectile, in that it has a polymer tip to facilitate rapid expansion, plus it helps retain bullet form if knocked. The tips are all green and make very effective vermin control loads.
A solid copper bullet design that penetrates deeply before expanding. The X bullet is solid copper to eliminate core separation and the nose section has a hollow cavity to enable expansion. Instead of a hollow point, the TTSX uses a pointed polymer tip to increase ballistic coefficient values and further aid in bullet expansion.
A good deer bullet that combines a bonded lead core to avoid voids. This helps with concentricity and integrity on expansion. The polymer tip retains ballistic performance and the projectile expands predictably at the end of its trajectory.
A transition bullet from Hornady that combines an aerodynamic design for superior flight with rapid expansion. They have a thick jacket and an interlock ring to keep the rear lead portion secure in order to drive the bullet home.
This is a classic hunting bullet that I use a lot, as it is always a consistently good performer. Typically a soft lead pointed bullet, they have a good BC and expand well down range. They are available in both flat and boat tail designs. The newer, Tipped GKs mean even more ballistic advantage in retained down range.
A more substantial bullet design from Speer for larger species of game. The flat base design has a protected soft nose to avoid damage, with the nose section of the jacket possessing thin, fluted sections to allow expansion. The inner lead core is bonded to the copper jacket in order to avoid separation. Grand Slams hit hard and cause minimal meat damage.
A great bullet from Nosler that has an integral partition of copper across its midsection. This allows the front, thinner jacket to expand more quickly whilst the shielded rear section continues to drive forward unaffected to allow deeper penetration.
These factors are important when it comes to a bullet’s trajectory and down range performance.
Sectional Density (SD) is simply the bullet’s calibre or diameter in relation to the weight of the projectile. It is calculated by dividing the bullet’s weight by the square of its diameter, so a 150-grain .30 calibre bullet would be 0.226. SD relates to a bullet’s ability to perform on game in relation to its penetrating abilities, as all 150-grain .308 calibre bullets have the same SD, regardless of shape. However, having a high SD is not the whole story, as it does not convey the bullet’s internal construction and how it will expand on target, so you need to choose a bullet suitable for its end use.
The Ballistic Coefficient (BC) tells a shooter how aerodynamic the bullet is. Working out a BC is more difficult than SD figures but is derived from a bullet’s ability to overcome air resistance when compared to a 1” boat tail spitzer standard ballistic form. I use the QuickLoad and QuickTarget computer programs to calculate multiple BC values, giving me exact trajectory curves for the ammunition that I use. The drop data can then be taped to a rifle stock for future reference.
Let’s look at one calibre, one weight and at one velocity to see how the BC alters the velocity, energy and trajectory towards your deer.
A lot of figures, but all very interesting. The data shows how the bullet shape affects performance. It should give you an idea of what to expect from different shaped bullets, however, different velocities, calibres and bullet construction will change the performance.
You can see how the higher BC bullets show better retention of energy down range and less drop/wind drift. All good, but you may need a round-nose bullet or Grand Slam for bigger game at close range, where the blunter point and harder bullet construction penetrates deeper. The choice is yours.
Norman Clark Gunsmiths www.normanclarkgunsmith.com
Edgar Brothers www.edgarbrothers.com
Henry Kranks www.henrykrank.com
Hannam’s Reloading www.hannamsreloading.com
Reloading Solutions www.reloadingsolutions.com