Analyzing an Ammo Box

There are a lot of numbers on a box of ammunition, and for a new shooter they can be confusing. Luckily, once you know what you’re looking at, picking the right ammunition can be a simple process.

Rifle & Pistol Boxes

Rifle and pistol boxes are usually pretty straight forward. The first thing to look for is whether or not the ammunition is reloaded. Most boxes of remanufactured ammunition will be labelled clearly. Some remanufactured ammunition is better than other. LakOrr Munitions, based out of South Dakota, sells custom made remanufactured ammunition that is high quality and dependable. When purchasing remanufactured ammunition, it’s important to know and be able to trust the source it’s coming from.

The caliber is usually listed plainly on the side of the box. It’s important to pay close attention this, since small details in caliber names can be the difference between well-functioning ammunition and a blown up firearm.

Frequently, right below the caliber, manufacturers will list the bullet size and type. Bullet weights are measured in grains, a unit of measurement nominally based on the mass of a single seed of cereal that is equivalent to about 64.8 milligrams. Different calibers will have different bullet weights, common bullet weights of a 9mm bullet for example include 147 gr., 124 gr. and 115 gr. Different guns will function differently with different bullet grains, and some will shoots the different weights more or less accurately.

LakOrr Munitions, based out of South Dakota, sells custom made remanufactured ammunition that is high quality and dependable. (Find out more at LakOrr Munitions, based out of South Dakota, sells custom made remanufactured ammunition that is high quality and dependable.
(Find out more at


Bullet types are often abbreviated, the most common include Full Metal Jacket (FMJ) and Jacketed Hollow Point (JHP). Different bullet types serve different purposes, some are better for defensive purposes while some are more suitable for competition or target practice. Some guns will have trouble feeding certain bullet types, which is why it’s important to run your defensive ammunition through your gun to make sure it functions without a problem.

Many manufacturers will also list the muzzle velocity at different yardages on the bottom of their box. Muzzle velocity is useful for competitors interesting in calculating power factor, which will affect how they are scored, and those who want a certain grain to velocity ration for defensive purposes.

The Shotgun Box

Shotgun ammunition is measured differently than pistol ammunition, and different ammunition types will have different information on the box.

All shotgun ammunition boxes will list the gauge and length of cartridge. Pay close attention the gauge, as it’s easy to accidentally pick up a box of 12 gauge for your 20 gauge shotgun. A shotgun’s gauge is its bore diameter, it is determined by the weight of a solid sphere of lead that fits into the bore, for example a 1/12th lb. ball of lead will fit into a 12-gauge shotgun bore, and a 1/20th lb. ball of lead will fit into a 20-gauge shotgun bore.


Cartridge length affects the power of the load, since more powder can fit into longer shells. The most important thing to recognize when choosing length is what your gun is chambered to handle. While 3” shells will fit into a gun chambered for 2¾” loads they should never be shot in one. The length is determined by the length of shell after it is fired, and shooting a shell through a gun that is not chambered to handle it could result in disaster.

The next thing to look at on a shotgun round box is whether it is filled with birdshot, buckshot, or slugs. Slugs have one heavy lead pellet in them, while buckshot is filled with a few smaller lead pellets and birdshot is filled with many small lead BBs.

Slugs will list the weight of the slug on the package expressed in either grains or ounces. Buckshot sizes vary from 000 (triple aught) to No. 4 shot. Birdshot sizes vary from 1 to 6 (steel shot) or 2 to 12 (lead shot). The shot sizes indicate the size of the pellets contained in the round, larger numbers indicate smaller pellets. Smaller pellets will hit with less force, but have a wider spread. Slugs and buckshot are favorite for defensive situations, while birdshot is generally considered ideal for hunting birds or shooting clay sports.

There are also some unusual shotgun rounds, such as Winchester PDX, which contains several disks and several lead BBs. The PDX Defender rounds list the gauge, length and velocity rather than discussing pellet size or slug weight.

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