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ARMAG

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.25 ACP

Introduced 1905John BrowningCIP standard

Also known as 6.35×16mm SR Browning, 6,35 Browning — the same cartridge under different names, all of which find this page.

Dimensions and pressure

Generated from the schema, like every specification table on this site, so a figure recorded on this entry cannot be missing from the table.

Identity
Designed by
John Browning
Introduced
1905
Production
not recorded
Standards body
C.I.P.
Case type
Semi rimmed
Case shape
Straight
Dimensions
Bullet diameter
6.38 mm0.2512 insource

C.I.P. G1, maximum bullet diameter.

Bore diameter
not recorded
Case length
15.55 mm0.6122 insource

C.I.P. L3, maximum case length.

Overall length
23 mm0.9055 insource

C.I.P. L6, maximum cartridge overall length.

Rim diameter
7.65 mm0.3012 insource

C.I.P. R1.

Neck diameter
7 mm0.2756 insource

C.I.P. H2.

Base diameter
7.02 mm0.2764 insource

C.I.P. P1.

Pressure
Maximum pressure
120 MPa17,405 psisource

C.I.P. Pmax 1200 bar; 1 bar = 0.1 MPa exactly.

Pressure standard
C.I.P.

SAAMI and C.I.P. measure pressure differently and their figures are not interchangeable, which is why the body is always named beside the figure.

Loads

Velocity is recorded per barrel length as published. A gun page interpolates between these points and never projects beyond them.

Federal American Eagle 50 gr full metal jacket

Federal

Bullet mass
3.24 g50.00 grsource

Published as 50 grains.

Cartridge mass
not recorded
Bullet type
FMJ
G1 BC
not recorded
G7 BC
not recorded
Sourced velocity by barrel length
BarrelVelocity
50.8 mm2.000 in231.6 m/s759.8 fps

Chambered in

Computed from every entry that lists this cartridge. Nothing here is hand-maintained.

Gallery

A .25 ACP pistol cartridge lying on its side, a small round-nose full metal jacket bullet seated in a short brass semi-rimmed case.

Image credit

Title
File:25 ACP - FMJ - SB - 1.jpg
Author
Malis
Licence
Public domain
Source
https://commons.wikimedia.org/wiki/File:25_ACP_-_FMJ_-_SB_-_1.jpg
A .25 ACP (6.35mm Browning) cartridge loaded with an FMJ bullet, from a Sellier & Bellot studio series.

Detail

The .25 ACP is a semi-rimmed, straight-walled pistol cartridge John Browning designed in 1905 for FN’s Model 1906 vest-pocket pistol, the smallest of his self-loading designs. At 6.38 mm bullet diameter and a 15.55 mm case, it is among the smallest self-loading centrefire pistol cartridges to see wide production, built specifically for tiny blowback pocket autos rather than any duty or hunting role.

Its low 120 MPa C.I.P. pressure ceiling and light bullets keep muzzle energy modest even by the standards of a small pocket pistol — a trade Browning accepted deliberately in exchange for a cartridge and a gun both small enough to carry concealed with no holster at all. It remained the standard vest-pocket-pistol chambering across Europe and the Americas for most of the twentieth century, alongside the .32 ACP one size up.

This entry carries the full C.I.P. dimensional standard and one factory load, Federal’s American Eagle 50-grain full metal jacket rated at 231.6 m/s from a stated 2-inch test barrel. No ballistic coefficient for the round-nose FMJ bullet was found published anywhere free, so the cartridge computes a muzzle energy figure but no trajectory, and no photograph showing the cartridge beside a modern vest-pocket pistol was found under a usable licence.

References

  1. .25 ACP · 1358670197 · read 2026-09-01
  2. C.I.P. TDCC datasheet — 6,35 Browning · 2008-09-23 · read 2026-09-01
  3. American Eagle Handgun 25 Auto, 50 gr FMJ (product page) · read 2026-09-01

Last verified 2026-09-01 · review status: agent-populated