Smith & Wesson SD

The Smith & Wesson SD, formerly known as the Sigma, was Smith & Wesson's first venture into using synthetic materials in pistol construction, using high-strength polymer material for the frame. The pistol is similar to a Glock safe-action pistol in both its design and operation, leading to some controversy and speculation as to the legality of the pistol's patents.

Description
Created in 1994, the Sigma incorporates pre-set striker firing mechanism. It is available in both .40 S&W cartridge and 9×19mm Parabellum being one of the first pistols purpose-designed to handle the .40 S&W. Similar styled sub-compact designs in .380 ACP and 9×19mm were also manufactured. A limited number of these pistols were also chambered for the .357 SIG cartridge.

Legality
The Sigma series pistols were so similar to the competing Glock pistols that Glock sued Smith & Wesson for patent infringement. The case was settled out of court in 1997, with S&W agreeing to make alterations to the Sigma design and pay an undisclosed amount to Glock.

Former users

 * Western Australia Police
 * Afghanistan National Army, Border patrol and police (22,000+ handguns)