556NATO
Standard NATO infantry cartridge since the 1960s. Higher pressure than .223 Remington. Proven combat effectiveness with modern expanding ammunition. Excellent terminal ballistics, flat trajectory, and minimal recoil. The most popular rifle cartridge in America for good reason.
Best For
Ballistics (Typical Factory Load)
3,100
Muzzle Velocity
fps
1,300
Muzzle Energy
ft-lbs
62
Typical Bullet
grains
0.250
Ballistic Coeff.
G1 BC
🔧 Handloading Data
Reference load data for experienced reloaders. Always start at the start charge and work up. Consult official manuals before loading.
| Bullet | Powder | Start | Max | Velocity | COAL | Source |
|---|---|---|---|---|---|---|
| 55 gr (3.6 g) FMJ-BT | Hodgdon H335 | 23.0 gr 1.49 g |
25.3 gr 1.64 g |
3,203 fps | 2.250" | Hodgdon |
| 62 gr (4.0 g) SS109 | Hodgdon CFE 223 | 26.0 gr 1.68 g |
27.8 gr 1.8 g |
3,000 fps | 2.250" | Hodgdon |
📐 Measurement Guide for Reloaders
Powder Charge
Measured in grains (1 grain ≈ 0.065 grams) using precision digital or mechanical scales. Maintaining strict powder weight is crucial for safety and velocity consistency.
Cartridge Overall Length (COAL)
Total length from case base to bullet tip. Checked with digital calipers. Must be within manufacturer's specified range to fit and feed from your firearm's magazine.
Cartridge Base to Ogive (CBTO)
Precision shooters measure to the ogive — the curved part of the bullet that first contacts the rifling — for more accurate bullet seating depth and consistency.
Case Length & Headspace
Brass stretches with firing. Measure case length to know when to trim. Use headspace comparators to check shoulder bump-back during sizing.
Neck Tension
The grip the brass has on the bullet. Measured with ball micrometers by comparing neck wall thickness before and after bullet seating.
Pressure Signs
Inspect fired brass for over-pressure: flattened primers, ejector marks, case head expansion. If unsure, reduce charge and consult your load manual.
⚠️ Always consult established reloading manuals (Hodgdon, Hornady, Lyman) for your specific bullet and powder combinations. For experienced reloaders only.
Technical Specifications
| Type | Rifle |
Compatible Firearms (354)
Ultimax 102Z
IWI
Machine gun
Cabot 556NATO
Cabot
Pistol
Echelon 5.56 NATO
Echelon
Pistol
Howa 1500 Mini
Unknown
Pistol
Kahr T556NATO
Kahr
Pistol
Nighthawk
Nighthawk
Pistol
Saiga
Unknown
Pistol
Vepr-223
Unknown
Pistol
Vepr-416
Unknown
Pistol
Manurhin MR74 556NATO
Manurhin
Revolver
AK Advanced
Kalashnikov
Rifle
AK Alpha
Kalashnikov
Rifle
AK Apex
Kalashnikov
Rifle
AK Sport
Kalashnikov
Rifle
AK Stealth
Kalashnikov
Rifle
AK Tactical
Kalashnikov
Rifle
AK-102
Kalashnikov
Rifle
AK-104
Kalashnikov
Rifle
AK-105
Kalashnikov
Rifle
AK-12
Kalashnikov
Rifle
AK-201
Kalashnikov
Rifle
AK-202
Kalashnikov
Rifle
AK-203
Kalashnikov
Rifle
American Tactical Tactical Carbine
American Tactical
Rifle
American Tactical Tactical Carbine Gen 2
American Tactical
Rifle
American Tactical Tactical Carbine V2
American Tactical
Rifle
Apex
Windham Weaponry
Rifle
Apex Rifle
Windham Weaponry
Rifle
Arsenal M4
Arsenal
Rifle
B-14 Varmint
Bergara
Rifle
BCM AR15 V1
Bravo Company
Rifle
BCM AR15 V10
Bravo Company
Rifle
BCM AR15 V11
Bravo Company
Rifle
BCM AR15 V12
Bravo Company
Rifle
BCM AR15 V13
Bravo Company
Rifle
BCM AR15 V14
Bravo Company
Rifle
BCM AR15 V15
Bravo Company
Rifle
BCM AR15 V16
Bravo Company
Rifle
BCM AR15 V17
Bravo Company
Rifle
BCM AR15 V18
Bravo Company
Rifle
BCM AR15 V19
Bravo Company
Rifle
BCM AR15 V2
Bravo Company
Rifle
BCM AR15 V20
Bravo Company
Rifle
BCM AR15 V21
Bravo Company
Rifle
BCM AR15 V22
Bravo Company
Rifle
BCM AR15 V23
Bravo Company
Rifle
BCM AR15 V24
Bravo Company
Rifle
BCM AR15 V25
Bravo Company
Rifle
BCM AR15 V26
Bravo Company
Rifle
BCM AR15 V27
Bravo Company
Rifle
BCM AR15 V28
Bravo Company
Rifle
BCM AR15 V29
Bravo Company
Rifle
BCM AR15 V3
Bravo Company
Rifle
BCM AR15 V30
Bravo Company
Rifle
BCM AR15 V31
Bravo Company
Rifle
BCM AR15 V32
Bravo Company
Rifle
BCM AR15 V33
Bravo Company
Rifle
BCM AR15 V34
Bravo Company
Rifle
BCM AR15 V35
Bravo Company
Rifle
BCM AR15 V36
Bravo Company
Rifle
BCM AR15 V37
Bravo Company
Rifle
BCM AR15 V38
Bravo Company
Rifle
BCM AR15 V39
Bravo Company
Rifle
BCM AR15 V40
Bravo Company
Rifle
BCM AR15 V41
Bravo Company
Rifle
BCM AR15 V42
Bravo Company
Rifle
BCM AR15 V43
Bravo Company
Rifle
BCM AR15 V44
Bravo Company
Rifle
BCM AR15 V45
Bravo Company
Rifle
BCM AR15 V46
Bravo Company
Rifle
BCM AR15 V47
Bravo Company
Rifle
BCM AR15 V48
Bravo Company
Rifle
BCM AR15 V49
Bravo Company
Rifle
BCM AR15 V5
Bravo Company
Rifle
BCM AR15 V6
Bravo Company
Rifle
BCM AR15 V7
Bravo Company
Rifle
BCM AR15 V8
Bravo Company
Rifle
BCM AR15 V9
Bravo Company
Rifle
BCM Competition Rifle
Bravo Company
Rifle
BCM Custom Build Rifle
Bravo Company
Rifle
BCM Hybrid Rifle
Bravo Company
Rifle
BCM Spec Ops Rifle
Bravo Company
Rifle
Badland
Windham Weaponry
Rifle
Basin
Windham Weaponry
Rifle
Browning Varmint
Browning
Rifle
Bushmaster ACR-E
Bushmaster
Rifle
Bushmaster ACR-X
Bushmaster
Rifle
Bushmaster CQB
Bushmaster
Rifle
Bushmaster Carbine-S
Bushmaster
Rifle
Bushmaster Composite
Bushmaster
Rifle
Bushmaster Custom Build
Bushmaster
Rifle
Bushmaster Custom Series
Bushmaster
Rifle
Bushmaster Custom-S
Bushmaster
Rifle
Bushmaster Custom-Z
Bushmaster
Rifle
Bushmaster Field Series
Bushmaster
Rifle
Bushmaster Lightweight
Bushmaster
Rifle
Bushmaster Micro Max-T
Bushmaster
Rifle
Bushmaster Semi-Auto
Bushmaster
Rifle
Bushmaster Sporter
Bushmaster
Rifle
Bushmaster Tactical Series
Bushmaster
Rifle
Bushmaster Tactical Varmint
Bushmaster
Rifle
Bushmaster Varmint
Bushmaster
Rifle
Bushmaster Varmint-X
Bushmaster
Rifle
CQB Special
Windham Weaponry
Rifle
CZ 527
CZ
Rifle
CZ Bren 2
CZ
Rifle
CZ Bren G
CZ
Rifle
Canyon
Windham Weaponry
Rifle
Century Classic 556
Century
Rifle
Century Hunter 556
Century
Rifle
Century Specialist 556 V2
Century
Rifle
Century Stealth 556 V2
Century
Rifle
Century Tactical 556
Century
Rifle
Century Varmint 556
Century
Rifle
Compact Carbine
Windham Weaponry
Rifle
Custom Build
Windham Weaponry
Rifle
Custom Match
LaRue
Rifle
DD V7 AR 5.56 Rifle
Daniel الزاويه Defense
Rifle
DD V7 Rifle
Daniel Defense
Rifle
DD V7M 5.56 Rifle
Daniel Defense
Rifle
DD V7S 5.56 Rifle
Daniel Defense
Rifle
DPMS Varmint
DPMS
Rifle
Defender 5.56
Windham Weaponry
Rifle
Desert
Windham Weaponry
Rifle
Duty Rifle
Windham Weaponry
Rifle
Evo Carbine
Windham Weaponry
Rifle
FAMAS
GIAT
Rifle
FN FNC-A
FN Herstal
Rifle
FN FNC-C
FN Herstal
Rifle
FN FNC-D
FN Herstal
Rifle
FN FNC-E
FN Herstal
Rifle
FN FNC-F
FN Herstal
Rifle
FN FNC-G
FN Herstal
Rifle
FN FNC-H
FN Herstal
Rifle
FN FNC-I
FN Herstal
Rifle
FN FNC-K
FN Herstal
Rifle
FN FNC-L
FN Herstal
Rifle
FN FNC-M
FN Herstal
Rifle
FN FNC-P
FN Herstal
Rifle
FN FNC-R
FN Herstal
Rifle
FN FNC-T
FN Herstal
Rifle
FN FNC-V
FN Herstal
Rifle
FN FNC-W
FN Herstal
Rifle
FN FNC-X
FN Herstal
Rifle
FN FNC-Y
FN Herstal
Rifle
FN FNC-Z
FN Herstal
Rifle
FN FNM Minimi
FN Herstal
Rifle
FN Fusil 20
FN Herstal
Rifle
FN Fusil 55
FN Herstal
Rifle
Field Rifle
Windham Weaponry
Rifle
Forest
Windham Weaponry
Rifle
Gorge
Windham Weaponry
Rifle
Heavy Barrel Rifle
Windham Weaponry
Rifle
Highland
Windham Weaponry
Rifle
Hunter Series
Windham Weaponry
Rifle
KAC AR15
Knight's Armament
Rifle
KAC Adv
Knight's Armament
Rifle
KAC Apex
Knight's Armament
Rifle
KAC Carbine
Knight's Armament
Rifle
KAC Compact
Knight's Armament
Rifle
KAC Custom
Knight's Armament
Rifle
KAC E3
Knight's Armament
Rifle
KAC E4
Knight's Armament
Rifle
KAC End
Knight's Armament
Rifle
KAC Expert
Knight's Armament
Rifle
KAC Light
Knight's Armament
Rifle
KAC M1
Knight's Armament
Rifle
KAC M13
Knight's Armament
Rifle
KAC M16
Knight's Armament
Rifle
KAC M27
Knight's Armament
Rifle
KAC M4
Knight's Armament
Rifle
KAC Master
Knight's Armament
Rifle
KAC Peak
Knight's Armament
Rifle
KAC Pro
Knight's Armament
Rifle
KAC Recon
Knight's Armament
Rifle
KAC Rugged
sKAC
Rifle
KAC SR15
Knight's Armament
Rifle
KAC SR3
Knight's Armament
Rifle
KAC Scout
Knight's Armament
Rifle
KAC Slim
Knight's Armament
Rifle
KAC Spec
Knight's Armament
Rifle
KAC Special
Knight's Armament
Rifle
KAC Stealth
Knight's Armament
Rifle
KAC Tactical
Knight's Armament
Rifle
KAC Top
Knight's Armament
Rifle
KAC Zenith
Knight's Armament
Rifle
LWRC DW 5.56
LWRC
Rifle
LWRC MRR 5.56
LWRC
Rifle
LWRC SPR 5.56
LWRC
Rifle
LWRC VR 5.56
LWRC
Rifle
LaRue Custom Build
LaRue
Rifle
LaRue Custom Lightweight
LaRue
Rifle
LaRue Precision Spec
LaRue
Rifle
LaRue Precision Varmint
LaRue
Rifle
Larue M1
LaRue
Rifle
Lightweight Carbine
Windham Weaponry
Rifle
M14 Tactical Rifle
Smith & Wesson
Rifle
M16A1
Colt
Rifle
M4 Carbine
Windham Weaponry
Rifle
Marksman Rifle
Windham Weaponry
Rifle
Match Rifle
LaRue
Rifle
Match Series
Windham Weaponry
Rifle
Model 1876 Single Shot
Winchester
Rifle
Model 700 Varmint
Remington
Rifle
Model 722
Remington
Rifle
Nobel
Weatherby
Rifle
Nosler American Predator
Nosler
Rifle
Noveske Gen 1
Noveske
Rifle
Noveske Gen 1
Noveske
Rifle
POF 556NATO Model
POF
Rifle
PSA DMR
Palmetto State Armory
Rifle
PTR 556NATO
PTR
Rifle
Pathfinder
Windham Weaponry
Rifle
Peak
Windham Weaponry
Rifle
Plateau
Windham Weaponry
Rifle
Precision Rifle
Windham Weaponry
Rifle
RR AR-15 Classic
Rock River Arms
Rifle
RR AR-15 Classic Gen 2
Rock River Arms
Rifle
RR AR-15 Compact Carbine
Rock River Arms
Rifle
RR AR-15 Compact Sporter
Rock River Arms
Rifle
RR AR-15 Duty Carbine
Rock River Arms
Rifle
RR AR-15 Duty Sporter
Rock River Arms
Rifle
RR AR-15 Field
Rock River Arms
Rifle
RR AR-15 Hunter
Rock River Arms
Rifle
RR AR-15 Hunter Carbine
Rock River Arms
Rifle
RR AR-15 Hunter Gen 2
Rock River Arms
Rifle
RR AR-15 Hunter Match
Rock River Arms
Rifle
RR AR-15 Lightweight
Rock River Arms
Rifle
RR AR-15 Lightweight Carbine
Rock River Arms
Rifle
RR AR-15 Lightweight Sporter
Rock River Arms
Rifle
RR AR-15 Match
Rock River Arms
Rifle
RR AR-15 Match Carbine
Rock River Arms
Rifle
RR AR-15 Match Gen 2
Rock River Arms
Rifle
RR AR-15 Match Gen 3
Rock River Arms
Rifle
RR AR-15 Match Sporter
Rock River Arms
Rifle
RR AR-15 Precision Carbine
Rock River Arms
Rifle
RR AR-15 Precision Sporter
Rock River Arms
Rifle
RR AR-15 Sport
Rock River Arms
Rifle
RR AR-15 Sporter Carbine
Rock River Arms
Rifle
RR AR-15 Tactical Match
Rock River Arms
Rifle
RR AR-15 Tactical Sporter
Rock River Arms
Rifle
RR AR-15 Target
Rock River Arms
Rifle
RR AR-15 Varmint
Rock River Arms
Rifle
RR AR-15 Varmint Carbine
Rock River Arms
Rifle
RR AR-15 Varmint Gen 2
Rock River Arms
Rifle
RR AR-15 Varmint Sporter
Rock River Arms
Rifle
Range Rifle
LaRue
Rifle
Ranger Carbine
Windham Weaponry
Rifle
Ridge Runner
Windham Weaponry
Rifle
River
Windham Weaponry
Rifle
Robinson Armament M4A1
Robinson Armament
Rifle
Robinson Armament M4A1-Advanced
Robinson Armament
Rifle
Robinson Armament M4A1-Custom
Robinson Armament
Rifle
Robinson Armament M4A1-E
Robinson Armament
Rifle
Robinson Armament M4A1-Elite
Robinson Armament
Rifle
Robinson Armament M4A1-Expert
Robinson Armament
Rifle
Robinson Armament M4A1-Master
Robinson Armament
Rifle
Robinson Armament M4A1-Precision
Robinson Armament
Rifle
Robinson Armament M4A1-Pro
Robinson Armament
Rifle
Robinson Armament M4A1-S
Robinson Armament
Rifle
Robinson Armament M4A1-Special
Robinson Armament
Rifle
Robinson Armament M4A1-Stealth
Robinson Armament
Rifle
Robinson Armament M4A1-Tactical
Robinson Armament
Rifle
Robinson Arms M4A1-Compact
Robinson Armament
Rifle
Robinson Arms M4A1-Customized
Robinson Armament
Rifle
Robinson Arms M4A1-Heavy
Robinson Armament
Rifle
Robinson Arms M4A1-Light
Robinson Armament
Rifle
Robinson Arms M4A1-Series 1
Robinson Armament
Rifle
Robinson Arms M4A1-Series 10
Robinson Armament
Rifle
Robinson Arms M4A1-Series 11
Robinson Armament
Rifle
Robinson Arms M4A1-Series 12
Robinson Armament
Rifle
Robinson Arms M4A1-Series 2
Robinson Armament
Rifle
Robinson Arms M4A1-Series 3
Robinson Armament
Rifle
Robinson Arms M4A1-Series 4
Robinson Armament
Rifle
Robinson Arms M4A1-Series 5
Robinson Armament
Rifle
Robinson Arms M4A1-Series 6
Robinson Armament
Rifle
Robinson Arms M4A1-Series 7
Robinson Armament
Rifle
Robinson Arms M4A1-Series 8
Robinson Armament
Rifle
Robinson Arms M4A1-Series 9
Robinson Armament
Rifle
Robinson Arms M4A1-Standard
Robinson Armament
Rifle
Robinson Specter
Robinson
Rifle
Ruger American Predator
Ruger
Rifle
Ruger Bushmaster
Ruger
Rifle
Ruger Gunsite Scout
Ruger
Rifle
Ruger Gunsite Scout
Ruger
Rifle
Ruger MFG Rifle 12
Ruger
Rifle
Ruger Micro-14
Ruger
Rifle
Ruger Mini-14
Ruger
Rifle
Savage 112
Savage Arms
Rifle
Savage 114
Savage Arms
Rifle
Savage 116
Savage Arms
Rifle
Savage 12
Savage Arms
Rifle
Savage Axis
Savage Arms
Rifle
Savanna
Windham Weaponry
Rifle
Semi-Auto Sport
Windham Weaponry
Rifle
Standard Issue
Windham Weaponry
Rifle
Stealth Rifle
Windham Weaponry
Rifle
Steppe
Windham Weaponry
Rifle
Steyr AUG
Steyr
Rifle
Steyr AUG
Steyr
Rifle
Steyr GS4
Steyr
Rifle
Steyr LG3
Steyr
Rifle
Steyr LG4
Steyr
Rifle
Steyr LG60
Steyr
Rifle
Steyr LGS10
Steyr
Rifle
Steyr LGS11
Steyr
Rifle
Steyr LGS12
Steyr
Rifle
Steyr LGS4
Steyr
Rifle
Steyr LGS5
Steyr
Rifle
Steyr LGS6
Steyr
Rifle
Steyr LGS7
Steyr
Rifle
Steyr LGS8
Steyr
Rifle
Steyr LGS9
Steyr
Rifle
Steyr M9A1
Steyr
Rifle
Steyr M9A4
Steyr
Rifle
Steyr M9A5
Steyr
Rifle
Steyr M9A6
Steyr
Rifle
Steyr M9A7
Steyr
Rifle
Steyr M9A8
Steyr
Rifle
Steyr M9A9
Steyr
Rifle
Steyr STG
Steyr
Rifle
Steyr Scout
Steyr
Rifle
Summit
Windham Weaponry
Rifle
Summit Series
Windham Weaponry
Rifle
Tactical AR-15
Windham Weaponry
Rifle
Tactical Gen 2
Windham Weaponry
Rifle
Taiga
Windham Weaponry
Rifle
Tavor 21
IWI
Rifle
Tavor M
IWI
Rifle
Tavor M2
IWI
Rifle
Tavor MXS
IWI
Rifle
Tavor SAR
IWI
Rifle
Tavor X95
IWI
Rifle
Tavor XTS
IWI
Rifle
Tikka T3x Super Varmint
Sako/Tikka
Rifle
Timber
Windham Weaponry
Rifle
Vanguard
Windham Weaponry
Rifle
Vanguard Rifle
Windham Weaponry
Rifle
Varmint Build
LaRue
Rifle
Varmint Spec
Windham Weaponry
Rifle
Varmint Special
LaRue
Rifle
Volcanic Arms AR-15
Colt
Rifle
Wilderness Rifle
Windham Weaponry
Rifle
Winchester 70 Coyote
Winchester
Rifle
Winchester Model 70 Featherweight
Winchester
Rifle
Windham Custom
Windham Weaponry
Rifle
Windham Patrol
Windham Weaponry
Rifle
Windham Sport
Windham Weaponry
Rifle
Windham Sporter
Windham Weaponry
Rifle
Zenith Carbine
Windham Weaponry
Rifle
FN Minimi Mk3-N
FN Herstal
Smg
AK-VLT
Kalashnikov
Srifle
BCM AR15 V4
Bravo Company
Srifle
KAC Elite
Knight's Armament
Srifle