.32 NAA

History and design

Bottleneck handgun cartridge designs experienced early success and have had continuing development since at least the 7.65×25mm Borchardt or earlier, which led to the development of the 7.63×25mm Mauser (also known as the .30 Mauser), followed by the 7.62×25mm Tokarev. The benefits of bottleneck designs include smooth feeding and chambering and simple, robust headspacing.

The .32 NAA uses the .312" diameter bullet of the .32 S&W, .32 S&W Long, .32 H&R Magnum, and .327 Federal Magnum, and .32 ACP.

The .32 NAA is one of the most recent of a line of commercial bottleneck handgun cartridges. Renewed western interest in bottleneck handgun cartridges began with the .357 SIG in 1994 (necking a .40 S&W case down to a .355 bullet); followed by the .400 Corbon in 1996 (necking a .45 ACP case down to hold a .40 cal. bullet); and then the .25 NAA in 1999 (necking a .32 ACP case down to hold a .25 caliber bullet). 2015 saw the introduction of the 7.5 FK bottleneck cartridge by the Czech company FK BRNO.

Performance

The cartridge delivers in excess of 1222 ft/s velocity to a 60 grain (3.9 gram) proprietary bullet from Hornady. This generates 199 ft.lbf of energy from the 2.5" Guardian barrel (1453 ft/s & 287 ft.lbf from a 4" test barrel).

According to Phil W. Johnston, the 60 gr Corbon cartridge averaged 1204 fps, with an extreme spread of 69 fps and a standard deviation of 19 fps, for 193.09 ft-lbs of energy. When fired at ballistic gelatin, he obtained 6.25" of penetration, with expansion to 0.528" and 72% weight retention.

Extreme Shock Ammunition offers an "Enhanced Penetration Round" that sends a 60 gr. bullet at 1196 fps for 190 ft lbs of energy.

In fall 2012, Hornady released a .32 NAA Critical Defense load that propels a relatively heavy (thus higher sectional density), 80 grain JHP FTX bullet at 1,000 fps.

Handguns

The North American Arms Guardian .32 NAA is designed around this cartridge.

Diamondback Firearms offers .32 NAA conversion barrels (2.8") for their DB380 pistols.

Makarov.com once stocked barrels of two different lengths for converting Makarov pistols to .32 NAA.

References

References

1. ''Cartridges of the World 11th Edition'', Book by Frank C. Barnes, Edited by Stan Skinner, Gun Digest Books, 2006, {{ISBN. 0-89689-297-2 p.291
2. "North American Arms, 32 NAA Guardian, retrieved 2012 May 12".
3. "''Handguns'', "The Mouse Gun That Roared," retrieved 2012 May 12".
4. "Extreme Shock Ammunition, Enhanced Penetration Rounds, retrieved 2012 May 12".
5. "Hornady Manufacturing, 32 NAA 80 gr FTX Critical Defense, retrieved 2012 Nov 23".
6. [https://archive.today/20130629002345/http://diamondbackfirearms.com/product?id=12 Diamondback Firearms, .32 NAA Conversion Barrel for DB380, retrieved 2012 May 12]
7. [http://www.makarov.com/32naa/index.html Makarov.com, ''The .32 NAA Conversion for the Makarov Pistol'', retrieved 2012 May 12]