Rifle · NATO
5.56x45mm NATO
Standard military rifle cartridge for NATO forces.
- Caliber
- 0.2244″ · 5.7 mm
- Introduced
- 1980
- Case
- Rimless
- Parent
- .223 Remington
- Primary use
- Military, Target, Competition
- Status
- Active
- Introduced
- 1980
- Type
- Rifle
- Origin
- United States
- Inventor
- Eugene Stoner / Remington
- Manufacturer
- Remington Arms
- Standard
- NATO
- Status
- Active
- Availability
- Abundant
- Case capacity
- 28.5 gr H₂O
- Twist (typical)
- 1:7 to 1:9
- Primer
- Small Rifle
- Case type
- Rimless
- Max pressure
- 62,000 psi, SAAMI transducer
- Eff. range
- 600 yd
- Max range
- 4200 yd
- Recoil
- 3.8–5.5 ft·lb
Introduced by Remington Arms
Ballistics
Published velocity/energy data isn't available for 5.56x45mm NATO. Parent case: .223 Remington.
Performance
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
CIP TDCC · verified| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 5.70 | 0.224 | ✓ |
| Neck ⌀ | 6.43 | 0.253 | ✓ |
| Shoulder ⌀ | 9.00 | 0.354 | ✓ |
| Shoulder angle | 23° | — | ✓ |
| Base ⌀ | 9.58 | 0.377 | ✓ |
| Rim ⌀ | 9.60 | 0.378 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.14 | 0.045 | ✓ |
| Neck length | 5.15 | 0.203 | ≈ |
| Case length | 44.70 | 1.760 | ✓ |
| Overall length | 57.40 | 2.260 | ✓ |
Size vs familiar rounds
Drawn at true 1:1 — every case is accurate relative to the others. Absolute size depends on your screen's pixel density, so measuring one against a real ruler may be off. 5.56x45mm NATO is highlighted below.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
Suitable powders
23 reloading powders listed for 5.56x45mm NATO, fastest to slowest. Cross-reference in the finder →
Reloading costestimate cost per round vs factory
Estimate your cost per round and how it compares to factory. Inputs are yours — nothing is stored.
Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.
Firearms chambered in 5.56x45mm NATO
2,771 models chambered in 5.56x45mm NATO
Lineage
Connected reference
History
Developed in late 1950s by Remington and Eugene Stoner for the AR-15. Adopted by US military in 1964 for M16 rifle. Standardized by NATO in 1980. Civilian .223 Rem introduced in 1962.
FAQs
- What twist rate does 5.56x45mm NATO use?
- 5.56x45mm NATO typically uses a 1:7 to 1:9 twist rate.
- What bullet diameter is 5.56x45mm NATO?
- 5.56x45mm NATO uses a 0.2244″ (5.7 mm) diameter bullet.
- Is 5.56x45mm NATO still in production?
- 5.56x45mm NATO is active; typical availability is abundant.
- What is 5.56x45mm NATO used for?
- 5.56x45mm NATO is primarily used for military, target, competition, varmint.
- What is 5.56x45mm NATO based on?
- 5.56x45mm NATO is derived from the .223 Remington case.
- What are the best powders for 5.56x45mm NATO?
- Reloading powders commonly listed for 5.56x45mm NATO include Norma R1, S133, Shooters World Economy Rifle, Lovex S010, among 23 suitable options.
Sources & provenance
- Standard SAAMI — SAAMI cartridge & chamber drawing — 5.56x45mm NATO
- Standard C.I.P. — C.I.P. TDCC — Tables of Dimensions of Cartridges and Chambers
- Secondary Wikipedia — .222 Remington Magnum (states it is the basis of the 5.6x50) · parent_cartridge
- Secondary Wikipedia — .223 Remington · parent_cartridge archived
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 164 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
