The National Shooting Sports Foundation (NSSF) reports that over 12 billion rounds of ammunition are sold annually in the United States. With so many options available, errors in ammo selection are common and can lead to malfunctions, poor accuracy, or even firearm damage. Data from the Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI) highlights that mismatched ammunition is a leading cause of catastrophic firearm failures. Here are ten key mistakes shooters must avoid when choosing their ammunition.
Rimfire or Centerfire: The Primer Problem
Rimfire and centerfire cartridges may look similar, but are not interchangeable. Rimfire ammo, such as .22 LR, is ignited when the firing pin strikes the cartridge rim, while centerfire uses a primer in the cartridge base. SAAMI testing shows that attempting to fire rimfire rounds in centerfire chambers can cause extraction issues, while chambering a centerfire round in a rimfire firearm can damage the action. Knowing which ignition system your firearm uses is critical to both function and safety.
Caliber Confusion Can Be Dangerous
A 9mm Luger and a .380 ACP are close in size but not interchangeable. SAAMI has documented over 50 case studies where incorrect caliber use caused case ruptures or barrel obstructions. Even slight differences in case length, such as between a .223 Remington and a 5.56 NATO, affect chamber pressure. Using the wrong caliber can cause excessive wear, poor ballistics, or catastrophic firearm failure. Always confirm the firearm’s chamber marking against the ammo box to avoid serious mistakes.
Misleading Ammo Names Trap Buyers
Some cartridges carry confusing names that don’t reflect their true size. For example, a .38 Special actually uses a .357-inch bullet, and a .30-06 Springfield fires a .308-inch projectile. According to historical ammunition catalogs, many naming conventions were based on obsolete measurements or marketing decisions. These inconsistencies often trip up new buyers, leading to the purchase of incompatible rounds. Without referencing SAAMI specifications or reliable guides, it’s easy to end up with ammunition that doesn’t fit your firearm.
Bullet Construction Isn’t One-Size-Fits-All
Ammunition is sold with different bullet types- FMJ, hollow point, soft point, or ballistic tip and each serves a distinct purpose. FBI testing protocols show hollow points expand up to 1.7 times their diameter in ballistic gel, while FMJ rounds tend to over-penetrate. Choosing the wrong bullet type for self-defense or hunting can lead to unintended outcomes, including poor stopping power or excessive penetration. Understanding bullet construction ensures the round performs as intended for the task at hand.
Precision Loads for Hunting Success
Hunters often underestimate the importance of load selection. A .308 Winchester cartridge, for example, is available in bullet weights ranging from 150 to 180 grains, each designed for different game. Data from the Boone and Crockett Club indicates that improperly matched hunting loads contribute to wounding loss rates as high as 15% in big game hunts. Choosing the correct load for species, range, and environment is not only a matter of accuracy but also an ethical hunting practice.
Specialty Rounds Demand Respect
Armor-piercing, tracer, and incendiary rounds are not only restricted in many states but also hazardous in casual use. ATF data shows that improper civilian use of incendiary and tracer ammunition has contributed to dozens of wildfires in western states. Specialty rounds generate pressures or effects outside normal firearm design parameters, which can shorten barrel life or cause legal trouble. Unless there is a clear, lawful need, such rounds should be avoided by recreational shooters.
Grain Weight Makes a Difference
The weight of a bullet, measured in grains, directly influences recoil, velocity, and accuracy. A 115-grain 9mm bullet typically achieves 1,150 fps, while a 147-grain bullet averages closer to 950 fps, according to manufacturer ballistic charts. Lighter bullets tend to shoot flatter but deliver less momentum, while heavier bullets offer deeper penetration but more recoil. Selecting the wrong weight for your firearm’s twist rate or purpose can result in poor accuracy and inconsistent performance.
How Bullet Shape Alters Flight
Bullet design impacts aerodynamics, stability, and terminal performance. Spitzer-shaped bullets, with their pointed tips, retain velocity better over long distances compared to round-nose designs. Sierra Bullets’ ballistic data shows that streamlined projectiles maintain up to 25% more energy at 500 yards than blunt-nosed counterparts. For close-range plinking, shape may not matter, but for precision shooting or hunting, selecting the correct profile directly affects accuracy and effectiveness downrange.
Ballistic Coefficient: Numbers That Matter
The ballistic coefficient (BC) measures how efficiently a bullet cuts through air resistance. A higher BC means less drop and drift, especially at long ranges. Hornady’s ballistics tables show that a bullet with a BC of .500 drops about 45 inches at 500 yards, while a similar bullet with a BC of .300 drops over 60 inches. Shooters buying ammo for long-range use must check BC values to ensure predictable performance in wind and distance shooting.
Read the Label, Not the Looks
Two cartridges can look almost identical but perform very differently. For example, a .300 Winchester Magnum and a .300 Weatherby Magnum both use .308-inch bullets but differ in case dimensions and chamber pressures. Visual inspection alone is unreliable, as slight dimensional changes can increase chamber pressure by tens of thousands of PSI. SAAMI and NRA safety guidelines both emphasize that ammunition must always be verified by reading the box label and matching it to the firearm’s barrel stamp.
