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Lindcott Armory

Revolver · SAAMI

.45 Auto Rim

Also known as .45 AR · .45 Automatic Rimmed

Rimmed version of .45 ACP designed for use in revolvers without moon clips.

Caliber
0.452″ · 11.481 mm
Introduced
1920
Case
Rimmed
Parent
.45 ACP
Primary use
Self Defense, Target
Status
Active

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VelocityBeing verified
EnergyBeing verified
Typical grains230 · 255 gr
Identity
Introduced
1920
Type
Revolver
Origin
United States
Inventor
Peters Cartridge Company
Manufacturer
Peters, Winchester, various
Standard
SAAMI
Status
Active
Availability
Limited
Build
Case capacity
26.7 gr H₂O
Twist (typical)
1:16
Primer
Large Pistol
Case type
Rimmed
Pressure & range
Max pressure
17,400 psi
Eff. range
50 yd
Max range
100 yd
Recoil
3–5 ft·lb
Subsonic
Capable

Ballistics

Published velocity/energy data isn't available for .45 Auto Rim. Parent case: .45 ACP.

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 ⌀ 11.480.452 ✓
Neck ⌀ 11.900.469 ✓
Shoulder ⌀ n/a
Shoulder angle n/a
Base ⌀ 11.960.471 ✓
Rim ⌀ 13.100.516 ✓
Belt ⌀ n/a
Rim thickness 2.100.083 ~
Neck length n/a
Case length 22.840.899 ✓
Overall length 32.251.270 ~

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. .45 Auto Rim 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.

Firearms chambered in .45 Auto Rim

12 models in the database chamber .45 Auto Rim. Browse all →

S&W Model 625-JM3 .45 ACP 4-inch Jerry MiculekSmith & Wesson Model 625 JM .45 ACP 4-inch Performance CenterS&W Model 625 JM Jerry Miculek .45 ACP 4-inchS&W Model 625 .45 ACP 4-inchSmith & Wesson Model 625 .45 ACP 5-inchS&W Model 625 .45 ACP 4-inch Moon ClipSmith & Wesson S&W Model 625 .45 ACP 5-inchSmith & Wesson Model 625 Performance Center 45 ACP N-FrameSmith & Wesson Model 325 Night Guard .45 ACP 2.75-inchSmith & Wesson Model 625 Mountain Gun .45 ACP 4-inchSmith & Wesson S&W Model 25-2 4"S&W Model 25-3 .45 ACP 6.5-inch

Lineage

Immediate parent
.45 ACP
Family TreeOpen .45 Auto Rim in the interactive cartridge family tree

Connected reference

Loads20 factory loads for .45 Auto RimFirearmsFirearms in .45 Auto Rim

History

Developed in 1920 by Peters Cartridge Company for the S&W M1917 and Colt M1917 revolvers — WWII-era service revolvers that had been chambered in .45 ACP using half-moon clips during WWI. The .45 Auto Rim allowed the M1917 revolvers to function as standard revolvers without requiring clips. Still produced today for shooters who prefer to load .45-caliber revolvers individually rather than using moon clips.

FAQs

What twist rate does .45 Auto Rim use?
.45 Auto Rim typically uses a 1:16 twist rate.
What bullet diameter is .45 Auto Rim?
.45 Auto Rim uses a 0.452″ (11.481 mm) diameter bullet.
Is .45 Auto Rim still in production?
.45 Auto Rim is active; typical availability is limited.
What is .45 Auto Rim used for?
.45 Auto Rim is primarily used for self defense, target.
What is .45 Auto Rim based on?
.45 Auto Rim is derived from the .45 ACP case.

Sources & provenance

Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 17 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →