Ammo Brief: .356 TSW

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We take a quick look at .356 TSW, aka .356 Team Smith & Wesson, one weird step-cousin of a cartridge

The .356 TSW centerfire pistol cartridge was designed by Smith & Wesson in 1994 as an IPSC round. The .356 TSW fit into a 9mm magazine, and Smith & Wesson convinced Federal to load it and submit it for SAAMI-spec approval, where it saw promise as a Limited-class competition round.

However, because of a rules change, USPSA didn’t approve it for that class, and there were other rounds that were better choices for Open guns. Smith & Wesson scrapped the project, effectively killing the cartridge. Federal case heads and the box were marked “356 TSW.” The load was a 147-grain FMJ Match product number GM356SW.

General Comments

The TSW is simply a slightly longer 9mm case (9×21.5mm), and it uses ordinary 9mm bullets for reloading purposes. To meet IPSC’s major power factor back then, the TSW had to send a 124-grain 9mm bullet at about 1,450 fps. A .356 TSW performs on par with hot 9×21 IPSC loads or full-house .357 Sig loads, but it has an advantage over the .357 Sig.

The Sig cartridge is a bottleneck round, a .40 S&W case necked down to 9mm. The .356 TSW is a straight-walled 9mm casing, thus more .356 rounds can fit into a magazine. The .356 TSW was mainly chambered in 150 Smith & Wesson Model 3566 Performance Center .356 TSW pistols.

Loading Data and Factory Ballistics

Bullet (GRAINS/TYPE)	POWDER	GRAINS	VELOCITY	ENERGY	SOURCE
147 Federal Match FMJ	FL	FL	1,220	486	Federal GM356SW
124 Winchester FMJ	VV3N37	9.1	1,446	576	IPSC Loads List 2001

Editor's Note: This article is an excerpt of Gun Digest's Cartridge's Of The World.

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