Only fire 5.56 in a chamber marked 5.56 NATO or .223 Wylde. Bulk cases are below.

Rifle marked .223 Remington only? Shop 223 Remington ammo, or read .223 vs 5.56: the difference and which to buy.

5.56x45mm NATO Ammo Guide

5.56x45mm NATO is the standard chambering of the AR-15 and many other modern semi-auto rifles. It is a military cartridge, and much of what is sold as range ammo, such as M193 and M855, follows the military load specifications. It is closely related to the commercial .223 Remington, but the two are not loaded to the same pressure and the chambers differ slightly.

The rule of thumb: a rifle marked 5.56 NATO or .223 Wylde can fire both 5.56 and .223. A rifle marked .223 Remington only should be fed .223 Remington unless the manufacturer says 5.56 is approved. If you are not sure what your rifle is, check the barrel stamp.

Best 5.56 Ammo by Use

Range and Practice

For practice, the two workhorse loads are M193 (55 grain FMJ) and M855 (62 grain "green tip" with a steel penetrator). Both are made by several makers and usually come in boxes of 20 or cases of 500 to 1,000. Some indoor ranges ban steel-core or green tip ammo, so check before you go. Brass case 55 grain is the most common choice for a first case of ammo.

Self-Defense

For home defense with an AR-15, many shooters choose a soft-point or bonded load designed to expand rather than FMJ. Barnes, Hornady and Winchester make dedicated loads. Test a few magazines in your rifle first, and think about what is behind your target.

Hunting

5.56 is used on varmints, predators and hogs, usually with soft-point, polymer-tip or monolithic copper bullets. Some states set a minimum caliber or require expanding bullets for deer, and some do not allow .22 caliber rifles for big game at all. Check your state regulations before hunting with it.

5.56 Grain Weights and Bullet Types

Our 5.56 listings are mostly 55 and 62 grain, with heavier 64 to 77 grain loads, including 75 and 77 grain match loads. Heavier bullets generally need a faster barrel twist to stabilize, so check your barrel's twist rate before buying heavy match ammo. A 1:7 or 1:8 twist handles the heavy loads; slower twists are usually best with 55 grain.

Quick bullet-type key: FMJ (full metal jacket) is a lead core with a copper jacket that does not expand, the usual range load. JHP (jacketed hollow point) is designed to expand and is the usual defensive load. Soft point and polymer tip bullets are designed to expand and are common for hunting. Solid copper bullets are lead-free and are required for hunting in some areas. Frangible bullets are designed to break up on hard targets and are used at some indoor ranges and steel-target courses.

Brass, Steel and Aluminum Cases

Most 5.56 is loaded in brass cases, which are the most widely accepted at ranges and can be reloaded. Steel-case ammo, usually lacquer or polymer coated, often costs less per round but cannot be reloaded, and some ranges and some firearms do not accept it. Aluminum-case ammo, such as Blazer, is a budget option that is also not reloadable. Whatever the case material, the product title and box list the exact cartridge, bullet weight and bullet type, so match those to your gun and your use.

Storing 5.56 Ammo

Store ammunition in a cool, dry place away from heat sources and out of reach of children, ideally locked. Sealed ammo cans with a gasket help keep moisture out for long-term storage. Keep different calibers in labeled containers so the wrong cartridge never ends up in a magazine. If ammo is corroded, dented or has been wet, do not fire it.

5.56 NATO Ballistics: Common Load

Published velocity and energy for a common 55 grain 5.56 NATO load (M193-style).

Load key: FMJ = full metal jacket.

Figures are as published by Federal Premium on each product page (checked October 30, 2026). Velocity from your own barrel will differ.

5.56 Brands We Carry

As of October 30, 2026, this category lists 55 5.56 products. Brands we carry in 5.56 include Winchester Ammunition, Hornady, PMC, Frontier Cartridge, Sterling, Aguila Ammunition, Barnes, Fiocchi Ammunition, Maxim Defense Industries, Armscor, Century Arms, Federal, Magtech, Prvi Partizan and Sellier & Bellot. Stock changes daily, so filter by availability in the grid above.

Buying 5.56 in Bulk vs by the Box

A 20- or 50-round box is the cheapest way to try a load in your gun. Once you know what runs well, larger cases of 250, 500 or 1,000 rounds almost always cost less per round. To compare listings fairly, divide the price by the round count to get the cost per round, and include shipping. Orders of $500 or more ship free, which usually makes a case the better deal. See what 5.56 has been costing in our Ammo Price Index, and browse bulk ammo.

How to Choose 5.56 Ammo

• Confirm the cartridge stamped on your barrel matches the box exactly.
• Pick the bullet type for the job: FMJ for practice, expanding bullets for defense and hunting.
• Buy a small quantity first and test it in your gun, then buy in bulk.
• Check your range rules for steel case, steel core or bi-metal bullets.
• Check your state and local laws before ordering.

Shipping and State Laws

Orders of $500 or more ship free. Ammunition orders under $500 ship for $15.99. Ammunition is not returnable. You must be of legal age to buy ammunition, and some states and cities restrict ammo shipments, require a license or background check, or limit certain bullet types. Read our ammo and magazine laws by state before ordering. Tactical Surplus USA has been selling firearms, ammunition and gear since 2022.

Related Calibers, Guides and Firearms

Related ammo: .223 Remington ammo, .223 vs 5.56 explained, 300 Blackout ammo, 7.62x39 ammo. Comparisons: 300 Blackout vs 5.56, 7.62x39 vs 5.56, ammo caliber chart. Shop AR-15 rifles, AR-15 uppers, AR-15 lowers, rifle magazines.