.25 NAA

Type

Pistol

Place of origin

United States

Production history

Designer

J.B. Wood

Designed

1999

Manufacturer

North American Arms

Produced

2002

Specifications

Parent case

.32 ACP

Case type

Rimless, bottlenecked

Bullet diameter

.251 in (6.4 mm)

Neck diameter

.276 in (7.0 mm)

Shoulder diameter

.333 in (8.5 mm)

Base diameter

.337 in (8.6 mm)

Rim diameter

.337 in (8.6 mm)

Rim thickness

.046 in (1.2 mm)

Case length

.745 in (18.9 mm)

Overall length

.960 in (24.4 mm)

Case capacity

9.75 gr H₂O (0.632 cm³)

Rifling twist

1 in 16 in (410 mm)

Primer type

Small Pistol

Maximum pressure

23,000 psi (160 MPa)

Ballistic performance

Bullet mass/type	Velocity	Energy
35 gr (2 g) XTP	1,200 ft/s (370 m/s)	121 ft·lbf (164 J)

Source(s): Cartridges of the World

The .25 NAA was introduced by North American Arms company for their smaller (height: 1/4" less; length: 1/3" less) and lighter (by approx. 25%) .32 ACP Guardian model. It is a new design based on .32 ACP, but it is a rimless case necked down to accept .251" diameter (.25 ACP) bullets and case is longer than a standard .32 ACP.

The cartridge was originally conceived and prototyped by gunwriter J.B. Wood and called the 25/32 JBW. North American Arms and Cor-Bon Ammunition then further developed the cartridge and the NAA Guardian .25 NAA pistol combination for production in consultation with Ed Sanow. The finalized cartridge and pistol were introduced at the 2004 SHOT Show.

It followed the successful introduction of two other commercial bottleneck handgun cartridges, the .357 SIG in 1994 (which necked a .40 S&W case down to accept .355 cal. bullets); and the .400 Corbon in 1996 (which necked a .45 ACP case down to accept .40 cal. bullets).

According to NAA's website, the .25 NAA's 35 gr bullet travels faster (1200 f.p.s.) and hits harder (20% more energy on average) than larger, .32 ACP caliber bullets.

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Wikipedia