Buy 5.56 NATO Ammo Online

The 5.56x45mm NATO is the most popular centerfire rifle cartridge in America
— the standard chambering of the AR-15 and the round most shooters feed their
rifles by the case. Affordable, accurate, and incredibly versatile, 5.56 NATO
is the go-to for range training, home defense, varmint and predator hunting, and
competition. At Trigger Ammo Store, we carry a deep selection of 5.56 ammunition
from budget-friendly bulk range loads to match-grade precision rounds, so you
can keep your AR fed for any purpose.

What Is 5.56x45mm NATO?

Adopted as a NATO-standard cartridge in 1980, the 5.56x45mm NATO was
developed from the .223 Remington and fires lightweight, high-velocity
.224-caliber bullets. Its flat trajectory, low recoil, and light weight (letting
shooters carry more rounds) made it the dominant military and civilian rifle
cartridge it is today. In the AR-15 platform, it delivers fast, accurate,
easy-shooting performance that’s just as at home on the range as in the field.

5.56 NATO vs .223 Remington — READ THIS BEFORE YOU BUY

This is the single most important thing to understand about 5.56 ammo. The
5.56 NATO and .223 Remington are nearly identical in external dimensions, but
they are NOT the same: 5.56 NATO is loaded to higher pressure and uses a
different chamber throat (leade). The safe-use rules are:

• Rifle chambered in 5.56 NATO: Can safely fire BOTH 5.56
  NATO and .223 Remington.
• Rifle chambered in .223 Remington only: Should fire ONLY
  .223 Remington. Firing 5.56 NATO in a .223-only chamber can produce excessive
  pressure and is not recommended.
• Rifle chambered in .223 Wylde: A hybrid chamber that
  safely shoots both 5.56 NATO and .223 Remington with excellent accuracy.

Always check your barrel’s marked chambering before buying. When in doubt,
consult your rifle’s manufacturer or a qualified gunsmith.

Common 5.56 Loads: M193, M855 & Match

• M193 (55 grain FMJ): The classic full metal jacket
  training and general-purpose load — affordable and reliable for high-volume
  range use.
• M855 (62 grain “green tip”): A 62-grain load with a steel
  penetrator tip, identifiable by its green-painted tip. Popular for general
  use; note some indoor ranges restrict steel-core ammo, so check range rules.
• Match (69–77 grain): Heavier match-grade loads (like
  77-grain options) deliver superior long-range accuracy for competition and
  precision work.

What Is 5.56 NATO Good For?

• Range & training: Affordable bulk ammo makes 5.56 the
  default choice for practice and high-round-count range days.
• Home & property defense: Proper defensive loads offer
  effective performance with manageable recoil from an AR-15.
• Varmint & predator hunting: Fast, flat-shooting loads
  excel on coyotes, prairie dogs, and other varmints.
• Competition: Match loads serve 3-gun, service rifle, and
  precision shooters.

Bulk 5.56 Ammo & Best Prices

5.56 is the king of bulk ammo, and buying by the case is the smart way to
shoot more for less. Whether you want a few hundred rounds for a range day or a
full case to stock up, our bulk 5.56 listings deliver low per-round pricing.
Watch our stock alerts for deals on popular M193 and M855 loads, which move
quickly.

Top 5.56 NATO Ammo Brands

We stock 5.56 ammunition from the manufacturers shooters trust, including
Federal, Winchester, PMC, Hornady, Speer, IMI, Magtech, and Lake City. From
mil-spec M193 and M855 to premium defensive and match loads, you’ll find the
right balance of price and performance for your AR-15.

Fast, Reliable Shipping

Orders ship quickly with secure, age-verified delivery in compliance with
all applicable federal, state, and local laws. By placing an order you confirm
you are at least 18 years of age (21+ where required) and that it is legal for
you to purchase and receive rifle ammunition at your delivery address. Some
states and localities restrict ammunition shipments — please review your local
regulations before ordering.

Frequently Asked Questions

Can I shoot 5.56 in a .223 rifle?

Only if your rifle is chambered in 5.56 NATO or .223 Wylde. If it’s marked
.223 Remington only, you should shoot only .223 Remington — firing 5.56 NATO in
a .223-only chamber can cause excessive pressure. Always check your barrel
markings.

What’s the difference between M193 and M855?

M193 is a 55-grain FMJ load; M855 is a 62-grain load with a steel penetrator
tip (green-painted). M855 is heavier and has the green tip; some ranges restrict
steel-core ammo, so check the rules where you shoot.

Do you sell 5.56 ammo in bulk?

Yes — 5.56 is one of our most popular bulk calibers. Check our bulk and case
listings for the best per-round pricing on in-stock loads.