.25 NAA
.25 NAA basic shape.png
.25 NAA basic shape
Place of originUnited States
Production history
DesignerJ.B. Wood
ManufacturerNorth American Arms
Parent case.32 ACP
Case typeRimless, 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 capacity9.75 gr H2O (0.632 cm3)
Rifling twist1 in 16 in (410 mm)
Primer typeSmall Pistol
Maximum pressure23,000 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[1]

The .25 NAA was introduced by North American Arms company, for a smaller and lighter Guardian model.

It is based on a .32 ACP case necked down to accept .251-inch diameter (.25 ACP) bullets.

History and design[]

The cartridge was originally conceivedof 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.[2]

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 caliber bullets); and the .400 Corbon in 1996 (which necked a .45 ACP case down to accept .40 caliber bullets).


According to NAA's website, the .25 NAA's 35 gr bullets travel faster (1,200 f.p.s.) and hit harder (20% more energy on average) than larger, .32 ACP caliber, bullets.

See also[]


  1. ^ Barnes, Frank C. (2006). Skinner, Stan (ed.). Cartridges of the World (11th ed.). Gun Digest Books. p. 288. ISBN 0-89689-297-2.
  2. ^ "25NAA Press Release" (Press release). North American Arms. Archived from the original on 2011-07-22. Retrieved 2018-11-26.

External links[]