Soon after the .357 SIG, other bottleneck commercial handgun cartridges appeared: the .400 Corbon (1996), necking the .45 ACP down to .40 caliber; the .440 Corbon (1998), necking down the .50 AE to .44 caliber; the .32 NAA (2002), necking the .380 ACP down to .32 caliber; and the .25 NAA (2004), necking the .32 ACP down to .25 caliber.