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Lindcott Armory

Rifle · SAAMI

7mm STW

Also known as 7mm Shooting Times Westerner · 7 STW

The original ultra-fast 7mm magnum — a long-case belted design pushing 140-grain bullets past 3,300 fps.

Caliber
0.284″ · 7.214 mm
Introduced
1979
Case
Belted
Parent
8mm Remington Magnum
Primary use
Hunting, Target
Status
Active

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VelocityBeing verified
EnergyBeing verified
Typical grains140 · 160 · 162 gr
Identity
Introduced
1979
Type
Rifle
Origin
United States
Inventor
Layne Simpson
Manufacturer
Remington / Nosler / Hornady
Standard
SAAMI
Status
Active
Availability
Limited
Build
Case capacity
102 gr H₂O
Twist (typical)
1:9
Primer
Large Rifle Magnum
Case type
Belted
Pressure & range
Max pressure
65,000 psi
Eff. range
800 yd
Max range
2000 yd
Recoil
30–42 ft·lb

Ballistics

Published velocity/energy data isn't available for 7mm STW. Parent case: 8mm Remington Magnum.

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.

SAAMI · verified
Measuremmin✓
Bullet ⌀ 7.210.284 ✓
Neck ⌀ 8.000.315 ✓
Shoulder ⌀ 12.370.487 ✓
Shoulder angle 25°— ✓
Base ⌀ 13.020.513 ✓
Rim ⌀ 13.510.532 ✓
Belt ⌀ 13.500.531 ~
Rim thickness 1.270.050 ✓
Neck length 7.060.278 ≈
Case length 72.392.850 ✓
Overall length 91.443.600 ✓

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. 7mm STW is highlighted below.

Factory loads

Verification

Being verified

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

Suitable powders

4 reloading powders listed for 7mm STW, fastest to slowest. Cross-reference in the finder →

MRP2N570Reloader 25Reloader 26
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 7mm STW

1 model in the database chamber 7mm STW. Browse all →

Remington Model 700 Sendero

Lineage

Immediate parent
8mm Remington Magnum
Family TreeOpen 7mm STW in the interactive cartridge family tree

Connected reference

Loads21 factory loads for 7mm STWReloading4 suitable powders — cross-referenceFirearmsFirearms in 7mm STW

History

Developed in 1979 by Layne Simpson, firearms editor at Shooting Times magazine, by necking down the 8mm Remington Magnum case to 7mm. Simpson nicknamed it the Shooting Times Westerner. It remained a wildcat for nearly two decades before Remington standardized it and began producing ammunition in 1996. At its introduction, it was the fastest production 7mm cartridge available, offering velocities that experienced hunters found genuinely useful at extreme range. Barrel life was the price — the large powder charge erodes throats quickly.

FAQs

What twist rate does 7mm STW use?
7mm STW typically uses a 1:9 twist rate.
What bullet diameter is 7mm STW?
7mm STW uses a 0.284″ (7.214 mm) diameter bullet.
Is 7mm STW still in production?
7mm STW is active; typical availability is limited.
What is 7mm STW used for?
7mm STW is primarily used for hunting, target.
What is 7mm STW based on?
7mm STW is derived from the 8mm Remington Magnum case.
What are the best powders for 7mm STW?
Reloading powders commonly listed for 7mm STW include MRP2, N570, Reloader 25, Reloader 26.

Sources & provenance

Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 21 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →