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Lindcott Armory

Rifle · SAAMI

.220 Swift

Also known as 220 Swift · 5.56x56mmSR

The first commercial cartridge to exceed 4,000 fps.

Caliber
0.2244″ · 5.7 mm
Introduced
1935
Case
Rimless
Parent
6mm Lee Navy
Primary use
Varmint
Status
Active

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VelocityBeing verified
EnergyBeing verified
Typical grains40 · 50 · 55 gr
Identity
Introduced
1935
Type
Rifle
Origin
United States
Inventor
Winchester
Manufacturer
Winchester Ammunition
Standard
SAAMI
Status
Active
Availability
Common
Build
Case capacity
47 gr H₂O
Twist (typical)
1:14
Primer
Large Rifle
Case type
Rimless
Pressure & range
Max pressure
62,000 psi
Eff. range
500 yd
Max range
800 yd
Recoil
5.5–8 ft·lb

Introduced by Winchester Ammunition

Ballistics

Published velocity/energy data isn't available for .220 Swift. Parent case: 6mm Lee Navy.

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 ⌀ 5.700.224
Neck ⌀ 6.600.260
Shoulder ⌀ 10.210.402
Shoulder angle 21°
Base ⌀ 11.360.447
Rim ⌀ 12.010.473
Belt ⌀ n/a
Rim thickness 1.240.049
Neck length 7.600.299
Case length 56.012.205
Overall length 68.072.680

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. .220 Swift is highlighted below.

Factory loads

Verification

Being verified

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

Suitable powders

9 reloading powders listed for .220 Swift, 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 .220 Swift

11 models in the database chamber .220 Swift. Browse all →

Ruger No. 1 Varminter 6.5 CreedmoorCooper Arms Model 21 Montana Varminter 22-250Cooper Arms Model 21 LVT 22-250Cooper Arms Model 21 220 Swift VarminterCooper Arms Model 21 22-250 ClassicNew Ultralight Arms Model 20 220 SwiftRuger No. 1 Varminter 6mm RemRuger No. 1 Varminter 220 SwiftRuger No. 1 V Varminter .25-06 RemRemington Remington 700 Classic 220 SwiftSavage 112 Varminter .220 Swift 26-inch

Lineage

Immediate parent
Direct descendants (2)
Family TreeOpen .220 Swift in the interactive cartridge family tree

Connected reference

History

Winchester introduced it in 1935 for the Model 54, then the Model 70. Based on the 6mm Lee Navy case necked to .224. Achieved stunning velocity for the era and set benchmarks that weren't surpassed commercially for decades. Gained a reputation as a barrel burner but remained the definitive varmint cartridge through the 1950s.

FAQs

What twist rate does .220 Swift use?
.220 Swift typically uses a 1:14 twist rate.
What bullet diameter is .220 Swift?
.220 Swift uses a 0.2244″ (5.7 mm) diameter bullet.
Is .220 Swift still in production?
.220 Swift is active; typical availability is common.
What is .220 Swift used for?
.220 Swift is primarily used for varmint.
What is .220 Swift based on?
.220 Swift is derived from the 6mm Lee Navy case.
What are the best powders for .220 Swift?
Reloading powders commonly listed for .220 Swift include Ramshot X-Terminator, Power Pro Varmint, IMR 8208 XBR, H322, among 9 suitable options.

Sources & provenance

Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 49 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →