.223 / 5.56

.223 / 5.56

.223 Remington and 5.56 NATO ammunition, in stock. Loaded in house in 20 round boxes and 150 round buckets, with real bullet weights and real availability rather than a permanent backorder button.

Before you order, one thing is worth checking: .223 and 5.56 are not the same cartridge. They share a bullet and case dimensions but not pressure, and the difference decides what is safe in your rifle. The guide below covers that in the first section, then bullet weight, twist rate and what to buy for each job.

Shooting this suppressed? See our 5.56 and .223 suppressors. For everything else we load, browse the caliber index.


Bullet weight, and what each one is for

This cartridge covers more jobs than any other on the site, and weight is how you pick. For quiet rifles, browse our blackout ammo as well.

WeightTypical useTwist needed
40 to 55grvarmint, fast and explosive on impact1:9 or faster
55gr FMJthe default practice and training load1:9 or faster
62grgeneral purpose, better barrier performance1:8 or faster
69 to 77gr matchprecision and longer range1:8 or 1:7

Light bullets leave faster and shed velocity quicker. Heavy bullets start slower, carry better at distance and need more spin to stabilise. That last point is the one people trip over.

Twist rate decides what your rifle can shoot

A barrel that will not stabilise a bullet produces keyholing, oval holes in paper and groups that make no sense.

A 1:9 barrel handles up to roughly 62 grains comfortably and struggles above that. A 1:8 barrel handles everything from 40 to 77 grains and is the most versatile choice. A 1:7 barrel is optimised for heavy 75 and 77 grain match bullets and will still shoot lighter loads perfectly well.

If you do not know your twist, buy 55 or 62 grain, which works in essentially every AR-15 ever built. Then test a heavier load before buying it by the bucket.

Buying by the bucket

.223 and 5.56 is the caliber where bulk buying pays most, because it is the one people shoot in volume. A 150 round bucket costs meaningfully less per round than the equivalent boxes, ships once instead of repeatedly, and stores in a sealed container rather than a shelf of cardboard.

Buy practice ammunition in quantity and specialist loads by the box. And confirm a load runs in your rifle before committing to a case: gas port sizes vary between makers, and a load that cycles perfectly in one AR can be marginal in another.

Store it cool, dry and dark. Moisture is what ruins ammunition, not age, so avoid unheated garages that swing in temperature and keep buckets off concrete floors.

Shipping and compliance

We ship within the USA to lawful destinations only, and orders over $300 ship free, which bulk orders generally clear. Ammunition rules vary by state and by city and it remains the buyer's responsibility to know them. See our shipping and delivery page. For chamber and pressure specifications, SAAMI is the industry authority.

Frequently asked questions

Is .223 the same as 5.56?

No. They share bullet diameter and case dimensions but not chamber or pressure. A 5.56 chamber safely fires both. A rifle marked .223 Remington only should not be fed 5.56, because the shorter leade raises pressure.

How do I know which my rifle is?

Read the barrel marking, not the receiver or the magazine, since the chamber is cut in the barrel. If it says 5.56 NATO or .223 Wylde, both cartridges are safe.

What is .223 Wylde?

A hybrid chamber that safely accepts both cartridges and is often more accurate with heavy match ammunition than a standard 5.56 chamber. It is usually the best choice when specifying a new barrel.

What bullet weight should I buy?

55 or 62 grain for practice and general use, which works in every common twist rate. 69 to 77 grain match for precision, provided your barrel is 1:8 or 1:7. Light 40 to 55 grain for varmint work.