man shooting rifle from a tree stand

Ammo Basics - Rifle

Anatomy of a Rifle Cartridge

Rimfire and Centerfire cutout; 1.Bullet 2.Case 3.Powder 4.Primer 5.Primer Mix

IGNITION SYSTEM: The two main types of rifle cartridges are rimfire and centerfire. Rimfire cartridges have primer mix located in the rim of the case. It is ignited when the firing pin strikes the rim and creates a small spark. The most common rimfire cartridges are 22 Long Rifle and 17 HMR. Centerfire cartridges have a primer which contains primer mix and a metal anvil inside of a small cup. The primer is placed in the center of the case head, and is ignited when the firing pin strikes the center of the primer cup, forming a spark between the cup and the anvil. Most centerfire cartridges can be reloaded.

CASE:The case is generally made of brass, contains all of the components and fits within the chamber of a firearm. Different calibers have different shapes and sizes of cases. Some cases have a neck to accommodate a bullet with a much smaller diameter than the body of the cartridge. Others have straight walls. The case must fit the chamber because of the extreme pressures created by the burning of the powder pushes the case out against the chamber. It is this pressure from expanding gases that pushes the bullet down the barrel. The caliber of the cartridge is stamped on the head of the case, and must be matched to the cartridge stamped on the gun barrel.

BULLETS: There is a wide array of bullet types, and they all perform differently. It is important to match the bullet to the application. Accuracy and precision of a bullet are important to consider, but in a hunting bullet it is equally important to consider a bullet's terminal performance, or what a bullet does when it hits and travels through a target. Factors important to terminal performance include penetration (how deep a bullet travels into a target), expansion (how much a bullet mushrooms to increase energy transfer to the target) and weight retention (how well the bullet stays intact).

Target bullets are designed to be accurate and/or inexpensive, but they generally don’t expand reliably for use on game. The full metal jacket (FMJ) is designed for military and target applications, and the jacket that extends from the point to base gives it a flat trajectory but poor expansion.

Hunting bullets are generally built to expand on impact. This creates a larger wound channel in the animal and transfers more energy, damaging even more tissue. Soft points are often used on medium game because the lead nose and tapered jacket are designed to expand as much as twice their original diameter on relatively light, thin-skinned animals. These are often considered the standard deer bullet, and can be found in Federal’s Power-Shok line. Federal’s Fusion bullet offers a jacket that is molecularly fused to the core, increasing weight retention.

All-copper monolithic bullets are generally designed for medium or larger game, and have high weight retention, but generally don’t expand as much as soft points. Their hollow point design peels back with hydrostatic pressure in game animals to expand the frontal diameter and penetrate deeply. Trophy Copper is an example

man shooting rifle from a tree stand

Trophy Bonded Bear Claw is perhaps the most famous bonded bullet. Bonding means the jacket and the core are joined together chemically, similar to welding. This helps keep the bullet together and reduce separation. While this bullet is a soft point, the solid limits how far the jacket can peel and mushroom, improving penetration on large and dangerous game.

The ultimate expanding hunting bullets offer designs that open up at all ranges, as well as retain weight to drive deep penetration. Federal Premium® Terminal Ascent is a perfect example. Its bonded construction penetrates deep on close targets, while the patented Slipstream® polymer tip initiates expansion at velocities 200 fps lower than comparable designs. Plus, the bullet’s long, sleek profile offers an extremely high ballistic coefficient, and its AccuChannel® groove technology improves accuracy and minimizes drag.

A hunting bullet that is designed not to expand is called a solid. These generally large-diameter bullets provide deep penetration and high weight retention for use on dangerous animals like Cape buffalo. An example is the Trophy Bonded Sledgehammer Solid, which features a thick bronze jacket that is bonded to the lead core, and a flat nose that minimizes deflection for a straight and deep wound cavity.

On the opposite end of the spectrum, varmint bullets like the Nosler Ballistic Tip have thin jackets that allow extremely fast, almost explosive expansion on impact. This design minimizes penetration to reduce pelt damage on furbearing predators and produce quick, clean kills.

Sighting in a Rifle

Rifle precision and accuracy hinge on properly sighting in. Follow these quick, easy steps to get on target.

  1. Before firing a shot, check sight screws or scope mounts. Also bore-sight with a collimator to estimate the point of impact and speed the sight-in process.
  2. Shoot from a solid rest, such as a benchrest or sand bags. Start at close range to make initial sight adjustments before verifying at longer ranges.
  3. From the rest, carefully squeeze off three aimed shots. The center of the resulting group of holes is the rifle’s point of impact. By adjusting your sights, you can move this point of impact to your desired target. Move open rear sights in the same direction you want the group to move. Adjust scopes following directions on the dials. Continue this process until the group is where you want it.
  4. Note that different ammunition might change the point of impact and necessitate re-sighting. If your rifle gets bumped or dropped, be sure to verify your point of impact.
man adjusting rifle scope


Trajectory is the arc a bullet follows as it leaves the firearm's muzzle. Bullets appear to rise because the barrel is angled up. The bullet's path crosses the line of sight twice—going up near the muzzle and down through the downrange zero (the distance at which the rifle is sighted in). About halfway between the muzzle and the zero, the bullet hits the highest point of its arc, then begins to drop. Velocity and bullet design determine the steepness of the arc. Low-velocity loads with round-nose bullets, if sighted for long ranges, will have a very high mid-range trajectory—possibly high enough to cause a miss on close-range targets.

man aiming rifle that is rested on a course obsticle

rifle trajectory patterns

Bullet Styles

Federal Rifle Styles: Terminal Ascent, HammerDown, Trophy Bonded Tip, Nosler Ballistic Tip, Trophy Bonded Bear Claw, Nosler Partition, Nosler Accubond, Swift Scirocco II, Barnes TSX, Berger Hybrid Hunter, Non-Typical, Fusion, Power-Shok, Power-Shok Copper, Trophy Bonded Sledgehammer Solid, Swift A-Frame, Woodleigh Hydro Solid, V-Max Varmint & Predator, Nosler Ballistic Tip Varmint & Predator, Speer TNT Green Varmint & Predator, Gold Medal Berger, Gold Medal Sierra MatchKing, Soft Point, Full Metal Jacket