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Lindcott Armory

Rifle · Obsolete / Non-standard

.297/250 Rook

Also known as 297/250 Rook · .297-250 Rook · .297/250

British rook rifle cartridge — .297 case necked to accept a .250 bullet.

Caliber
0.2535″ · 6.44 mm
Introduced
1880
Case
Rimmed
Primary use
hunting
Status
Obsolete

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VelocityBeing verified
EnergyBeing verified
Typical grains56 gr
Identity
Introduced
1880
Type
Rifle
Origin
United Kingdom
Inventor
Various British
Manufacturer
British gunsmiths / various
Standard
Obsolete / Non-standard
Status
Obsolete
Availability
Antique
Build
Case capacity
9 gr H₂O
Twist (typical)
1:14
Primer
Large Rifle
Case type
Rimmed
Pressure & range
Max pressure
18,000 psi
Eff. range
100 yd
Recoil
12–18 ft·lb
Subsonic
Capable

Ballistics

Published velocity/energy data isn't available for .297/250 Rook — an obsolete/collector cartridge.

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.

Wikipedia · approximate
Measuremmin
Bullet ⌀ 6.440.254 ~
Neck ⌀ 6.750.266 ·
Shoulder ⌀ 7.290.287 ·
Shoulder angle 7.5° ~
Base ⌀ 7.540.297 ·
Rim ⌀ 8.940.352 ·
Belt ⌀ n/a
Rim thickness 1.090.043 ·
Neck length 5.500.217
Case length 20.630.812 ·
Overall length 28.261.113 ·

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. .297/250 Rook is highlighted below.

Factory loads

Verification

Being verified

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

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.

Connected reference

History

Another British rook rifle cartridge, featuring a larger case than the .255 Rook while maintaining similar ballistics. Used in the classic British rook rifles for estate vermin control. The tradition of rook shooting with specialized rifles died out as rimfire cartridges became practical for the same purpose.

FAQs

What twist rate does .297/250 Rook use?
.297/250 Rook typically uses a 1:14 twist rate.
What bullet diameter is .297/250 Rook?
.297/250 Rook uses a 0.2535″ (6.44 mm) diameter bullet.
Is .297/250 Rook still in production?
.297/250 Rook is obsolete; typical availability is antique.
What is .297/250 Rook used for?
.297/250 Rook is primarily used for hunting.

Sources & provenance

Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 2 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →