223 / 5.56 AR-15 Ammo

Overview of .223 / 5.56 Ammo

Whether you load .223 Remington or 5.56 NATO, you are shooting the most widely used centerfire rifle cartridge in the United States. Developed in the late 1950s and adopted by the U.S. military as the M16's standard cartridge in 1964, .223/5.56 fires a .224-inch diameter bullet at high velocity with minimal recoil, making it equally at home on an AR-15 range day, a varmint hunt, or a precision rifle competition.

One thing every AR-15 owner needs to know: 5.56 NATO is loaded to higher pressure than .223 Remington and should not be fired in a rifle marked .223 Remington only. Rifles marked 5.56 NATO or .223 Wylde safely accept both. When in doubt, check your barrel stamp. For a full breakdown of the differences, see our 5.56 vs .223 guide.

Popular .223 / 5.56 Brands We Carry

• Federal .223 / 5.56 Ammo: including American Eagle 55gr and 62gr FMJ in 500-round cases
• PMC .223 / 5.56 Ammo: 55gr and 62gr M855 FMJ in 1,000-round cases at some of our lowest cost-per-round pricing
• Hornady .223 / 5.56 Ammo: including V-MAX varmint loads and Black 75gr OTM for precision shooting
• Winchester .223 / 5.56 Ammo: USA White Box FMJ and 5.56 NATO M855 loads
• Black Hills .223 / 5.56 Ammo: including 77gr OTM match loads, the standard for NRA High Power competition

Best .223 / 5.56 Ammo for Specific Uses

Why Buy .223 / 5.56 Ammo from BulkMunitions?

• In stock and ready to ship. We only list ammunition that is physically in our warehouse. No backorders.
• Next-business-day shipping from our Knoxville, TN warehouse on orders placed before our daily cutoff.
• Bulk pricing on top brands. The more you buy, the lower your cost per round. Case quantities deliver the best per-round price on every load we carry.
• We tithe 10% of profits to Christian-based, 2A-supporting organizations every quarter, and our customers vote on where it goes.

Frequently Asked Questions

Can I shoot 5.56 NATO ammo in a .223 Remington rifle?

It depends on your chamber. 5.56 NATO is loaded to higher pressure than .223 Remington and should not be fired in a rifle marked .223 Remington only. Rifles marked 5.56 NATO or .223 Wylde safely accept both. Always check your barrel stamp before mixing the two. For a full breakdown of the differences, see our 5.56 vs .223 guide.

What is the difference between M193 and M855?

M193 is the original 55gr FMJ load adopted in 1964, running approximately 3,250 fps. M855 is the current 62gr load with a steel penetrator core adopted in 1980. M855 offers better barrier penetration but fragments less reliably than M193 at close range, making M193 generally preferred for home defense use. M855 is sometimes restricted at indoor ranges due to its steel core, though it is not classified as armor-piercing under federal law.

Is .223 good for deer hunting?

.223 is legal for deer in most states and adequate inside 200 yards with a 60-77gr bonded load and precise shot placement. Some states have minimum caliber or energy requirements it may not meet, so verify your local regulations before heading out. Light varmint loads are not appropriate for deer-sized game. For larger rifle calibers suited to deer and elk, browse our full rifle ammo selection.