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Lindcott Armory

Rifle · SAAMI

.243 Winchester

Also known as .243 Win · 6x52mm

Dual-purpose cartridge.

Caliber
0.243″ · 6.172 mm
Introduced
1955
Case
Rimless
Parent
.308 Winchester
Primary use
Varmint, Hunting
Status
Active

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VelocityBeing verified
EnergyBeing verified
Typical grains90 · 95 · 100 gr
Identity
Introduced
1955
Type
Rifle
Origin
United States
Inventor
Winchester
Manufacturer
Winchester Ammunition
Standard
SAAMI
Status
Active
Availability
Abundant
Build
Case capacity
54.8 gr H₂O
Twist (typical)
1:9 to 1:10
Primer
Large Rifle
Case type
Rimless
Pressure & range
Max pressure
60,000 psi
Eff. range
400 yd
Recoil
8–12 ft·lb

Introduced by Winchester Ammunition

Ballistics

Published velocity/energy data isn't available for .243 Winchester. Parent case: .308 Winchester.

Performance

Best for Withheld until verified
Best for Withheld until verified
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
Measuremmin✓
Bullet ⌀ 6.170.243 ✓
Neck ⌀ 7.010.276 ✓
Shoulder ⌀ 11.530.454 ✓
Shoulder angle 20°— ✓
Base ⌀ 11.960.471 ✓
Rim ⌀ 12.010.473 ✓
Belt ⌀ n/a
Rim thickness 1.370.054 ✓
Neck length 6.110.241 ≈
Case length 51.942.045 ✓
Overall length 68.832.710 ✓

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. .243 Winchester is highlighted below.

Factory loads

Verification

Being verified

Advertised FPS, energy, and BC are withheld until loads clear verification.

Suitable powders

37 reloading powders listed for .243 Winchester, fastest to slowest. Cross-reference in the finder →

N530Accurate 2520RS52Norma 2012495AR 2207AR 2206HNorma 200Precision RifleAR 2208CFE 223N135N550IMR 4895H4895203-BAlliant Reloader 15H380N555Vihtavuori N140
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 .243 Winchester

12 models in the database chamber .243 Winchester. Browse all →

Browning X-Bolt Speed .30-06 SpringfieldBrowning X-Bolt Speed 6.5 CreedmoorCZ 600 LuxWeatherby Model 307 .308 WinWeatherby Model 307 Alpine 6.5 CreedmoorWeatherby Model 307 6.5 CreedmoorWeatherby Model 307 .28 NoslerWeatherby Model 307 .300 Win MagWeatherby Model 307 .243 WinWeatherby Model 307 Range XP .308 WinWeatherby Model 307 Alpine MDT 6.5 CreedmoorBrowning X-Bolt Speed .243 Win

Lineage

Immediate parent
.308 Winchester
Direct descendants (2)
.22-243 Winchester.243 Winchester Ackley Improved
Family TreeOpen .243 Winchester in the interactive cartridge family tree

Connected reference

Loads197 factory loads for .243 WinchesterReloading37 suitable powders — cross-referenceFirearmsFirearms in .243 Winchester

History

Introduced by Winchester in 1955. Instantly popular as combination varmint/deer rifle. Considered the minimum for ethical deer hunting in many states.

FAQs

What twist rate does .243 Winchester use?
.243 Winchester typically uses a 1:9 to 1:10 twist rate.
What bullet diameter is .243 Winchester?
.243 Winchester uses a 0.243″ (6.172 mm) diameter bullet.
Is .243 Winchester still in production?
.243 Winchester is active; typical availability is abundant.
What is .243 Winchester used for?
.243 Winchester is primarily used for varmint, hunting.
What is .243 Winchester based on?
.243 Winchester is derived from the .308 Winchester case.
What are the best powders for .243 Winchester?
Reloading powders commonly listed for .243 Winchester include N530, Accurate 2520, RS52, Norma 201, among 37 suitable options.

Sources & provenance

Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 188 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →