Shotgun shells are a marvel of engineering, combining precision, power, and practicality. But for those new to the world of shotguns—or even seasoned shooters—deciphering the numbers on a box of shotshells can be daunting. What do all those measurements, velocities, and sizes mean? This guide will help break it all down, so the next time you’re at the range or out in the field, you’ll know exactly what to pick up.
Start with the Gauge

The gauge is the first thing you’ll notice on a box of shotshells, and it’s crucial to match this number with your shotgun. Contrary to intuition, a smaller number indicates a larger shell size. For example, a 12-gauge is larger than a 20-gauge or a 28-gauge. On the other hand, a 10-gauge is even bigger than a 12-gauge. This numbering system is a throwback to how many lead balls of the same diameter would weigh a pound; for instance, 12-gauge means 12 such balls equal one pound.
Always check your shotgun barrel for its designated gauge. Using the wrong gauge can be dangerous, potentially causing malfunctions or damage to the firearm.
Chamber Length: Measure After Firing

Next, you’ll find the chamber length, often listed as two and three-quarters inches (2¾”), three inches, or even three and a half inches. This number refers to the length of the shell after it’s been fired. It’s important to match this number to your shotgun’s chamber size, which will also be indicated on the barrel.
While a longer shell might physically fit into a shorter chamber, firing it can lead to increased pressure and potentially damage the gun. As a rule of thumb, never use a shell longer than your shotgun’s chamber length.
Velocity: The Speed of Impact

The velocity listed on a shotshell box, measured in feet per second (fps), indicates how fast the shot leaves the barrel. Faster loads deliver more energy and can cover greater distances effectively, but they also tend to produce more recoil.
A typical target load might list a velocity of around 1,200 fps, while hunting or high-performance shells can exceed 1,500 fps. Choose the right velocity based on your intended use. For casual shooting, a lower-velocity shell can save your shoulder, while higher-velocity shells are better suited for hunting game at longer ranges.
Shot Charge: The Payload in the Shell

The shot charge, expressed in ounces, tells you how much shot (small pellets) is packed inside the shell. This can range from light loads like one ounce for target shooting to heavy loads of two ounces or more for turkey hunting.
Higher shot charges mean more pellets, which can improve your chances of hitting your target, especially at longer distances. However, they also produce more recoil. For activities like skeet shooting, lighter loads are generally preferred, while hunting often calls for heavier loads.
Shot Size: Tailoring to the Target

Shot size is a number that tells you the size of the individual pellets. Smaller numbers represent larger pellets. For instance, the #4 shot is larger than the #8 shot. Smaller shot sizes like #7½, #8, or #9 are ideal for clay targets or small game like doves. Larger shot sizes like #2 or BB are better for waterfowl or larger game birds.
Buckshot and slug loads are used for defense or hunting larger game. These have much larger pellets, and there are typically fewer of them in a shell.
Dram Equivalent: A Legacy Measurement

You might also encounter a term called “dram equivalent” on older or traditional shells. This is a nod to the days of black powder, where a dram (1/16 of an ounce) measured the powder charge. Today, this term helps correlate to the shell’s power and velocity, though most shooters rely on the listed velocity instead.
High Brass vs. Low Brass

The terms “high brass” and “low brass” refer to the height of the metal collar on the base of the shell. Historically, high brass was used for heavier loads because it helped reinforce paper shells against the pressure of black powder.
In modern times, it’s more of a visual cue. High brass often indicates a heavier hunting load, while low brass is used for lighter loads like target shooting.
Choosing the Right Shell for the Task

Understanding these numbers is critical for selecting the right shotshell for your activity. Hunting pheasants or ducks? You’ll likely want a heavier load with larger shot size. Heading to the range for a round of trap or skeet? A light target load with smaller shot size will do the trick.
It’s all about balance. Too heavy a load can lead to unnecessary recoil, while too light a load might lack the power or spread you need. By considering your activity and matching the shell specifications accordingly, you’ll ensure a safer and more enjoyable experience.
Safety First: Match Shell to Gun

Always double-check that the gauge, chamber length, and shell specifications match your shotgun. Using the wrong ammunition is not just ineffective – it’s dangerous. Inspect your firearm and your ammunition carefully before heading out.
Confidence Through Knowledge

Learning to read shotshell boxes is more than just a technical skill; it’s an empowering way to engage with your sport or hobby. When you understand the data on a shotshell box, you’re not just picking up ammo – you’re making informed choices that align with your goals, equipment, and safety.
Whether you’re a seasoned hunter or a weekend clay shooter, taking the time to understand these details will enhance your shooting experience. Remember, the right shell can make all the difference, so choose wisely and enjoy the sport responsibly.

Raised in a small Arizona town, Kevin grew up surrounded by rugged desert landscapes and a family of hunters. His background in competitive shooting and firearms training has made him an authority on self-defense and gun safety. A certified firearms instructor, Kevin teaches others how to properly handle and maintain their weapons, whether for hunting, home defense, or survival situations. His writing focuses on responsible gun ownership, marksmanship, and the role of firearms in personal preparedness.