Learn the key rifle ammo terms and how to choose reliable rounds for your needs
- Ammo choice is critical to safe and effective firing
- Ammo grade and grain effect consistency, safety, and accuracy
- Quality consideration and intended use are interlinked
- Speaking with an experienced ammo dealer will help you make a wise choice
Choosing the right ammo for your gun is as important as marksmanship training and staying current with firearm laws. A wise choice will help you achieve your goals with no adverse effects. A bad decision could see you failing in competition, damaging your rifle, or harming people and property. Let’s explore some common terms, round types, and ways rifle ammo can be used.
Common rifle ammo terms
Ammo grade is applied in a couple of ways. Match grade ammo is used for competition and designed for higher degrees of accuracy and performance consistency factors (like primers and powders) than standard grade rounds. Match grade ammo is thus more expensive and comes with a caveat: There is no accepted industry standard for this grading. Any manufacturer could make the claim without regulation to back it up.
Military-grade ammo, also called mil-spec, is available as surplus on the public market. This grade is generally tougher against the effects of corrosion and water, and it’s tested to NATO specifications. These specs are different from those used for civilian rounds and result in higher pressure ammo.
Thus, using mil-spec rounds safely takes knowledge. Coupling them with the wrong firearm can be hazardous, jamming bolts and chambers or causing other damage to the rifle. Military-grade rifle ammo is often found graded under an informal rating system of 1 to 3 (1 being best) that is not officially recognized by any grading body. There is also a middle ground in the form of XM ammo — civilian rounds made in a similar fashion to military ones.
Rifle ammunition grain
Ammo grain (abbreviated as gr) is the small unit of mass used to measure the weight of a bullet. It measures only the part that exits the barrel and not aspects like how much gunpowder or propellant is used in the cartridge. Ammo grain is calculated by multiplying the mass value by 7000 with 7000 grains equaling one pound of weight.
Grain affects a bullet’s trajectory, recoil, and terminal ballistics (the bullet’s ultimate effect on contact with a target). You will likely find that the caliber of your weapon has a standard grain. This is a good place to start before further exploring how other grains may help or hinder your firearm goals.
Types of rounds
There are many names and numbers attached to rifle ammo. A basic working knowledge of three main categories helps ammo shoppers more quickly find the right rounds for their purpose.
- FMJ (Full Metal Jacket): A very common and reliable ammo type that is also called “ball” in military circles. FMJ refers to their composition: a lead core covered with metal. The primary purpose of ball ammo is target penetration, which makes them a good choice for range shooters and general bullseye practice.
- Split/Hollow Point: Hollow points can be composed solely of copper or be copper-coated lead rounds. They are empty at their tips, expanding and sometimes fragmenting on impact with a target. This has two effects: The expansion causes a large wound while fragmentation prevents over-penetration.
- Specialty: These designs diverge from the standard ammo construction and include bullet designs like green tips, boat tails, and tracers. Green tips are a 62-grain cartridge with higher penetration due to its combination lead and steel core with a copper jacket. Boat tail rounds have a taper to the cartridge’s back end that allows for less drag. Tracer bullets leave a pyrotechnic trail when fired that allows shooters to view the trajectory of their shot.
This is a basic overview of three ammo designations. Wider options and how they relate to your firearm type and level of marksmanship are best discussed with a qualified ammunition dealer who can also advise you regarding how gun laws in your state could affect permitted ammo types.
Quality considerations and use context
These two factors are closely related. Buying cheaper ammunition in bulk is a good solution if you’re intending on only using it at a firing range — large quantities of ball ammo can usually be bought cost-effectively. Competitive shooters will want to budget for the higher-end, more expensive match-grade rounds so their performance won’t be compromised.
The penetrating power of range ammo may make it sound ideal for self-defense, but this isn’t the case when the physics and potential for unwanted harm are considered. For example, using ball ammo in a self-defense situation is powerful enough to go straight through a human target and continue on to cause further damage to people or property.
A hollow-point would be a more efficient self-defense ammo choice because it expands on impact and won’t go beyond the target. Hollow points are also a popular choice for hunters of larger game.
Lighter vs. heavier grains
In terms of grain, both lighter and heavier rifle ammo have their advantages and disadvantages. Higher grains offer a more stabilized shot along with greater penetration and expansion, but they also have more pronounced recoil than a lighter grain. Recoil effect is subjective based on the firearm owner and the weapon’s design, so this may be a negative for some users and not an issue for others. Heavier grains are less affected by wind, which can increase their accuracy in adverse conditions.
Lighter grains travel faster, fly straighter for longer (in certain weather), and deliver less recoil, which is again dependent on factors like firearm recoil management and user tolerance. These grains won’t penetrate as far as a heavier grain when it comes to terminal ballistics, making them less reliable in a self-defense scenario and better suited for the range where speed and distance are the only real concerns.
Hunter’s may also opt for lighter grains if hunting smaller animals as using them for larger game would only result in a wounded target that would have to be pursued. Anyone choosing lighter grains must also bear in mind that these bullets are more vulnerable to being affected by wind while in motion, which can impact their accuracy.
Explore your rifle ammo choices with Ammunition Depot
The “right” ammo for your rifle depends on numerous factors, but ultimately, it’s the one that performs reliably for the intended purpose while fitting your budget and your firearm. Ammunition Depot provides high-quality rifle ammunition by box or by bulk that you can browse based on multiple factors, including intended use, caliber, manufacturer, and more.
Our knowledgeable staff are also here to provide rifle ammo advice, so you can confidently and safely exercise your Second Amendment right. Drop by our contact page to learn more or ask us a question.