The .25 NAA is a pistol cartridge introduced by the North American Arms company in 2002.

It is based on a rimless version of the .32 H&R case, shortened to .745" and necked down to accept .251-inch diameter (.25 ACP) bullets.

The cartridge was originally conceived of and prototyped by gunwriter J.B. Wood, and called the "25/32 JBW".

[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).

and hit harder (20% more energy on average) than larger, .32 ACP caliber, bullets.