Ammo Brief: .243 WSSM

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We take a quick look at the oddly proportioned .243 Winchester Super Short Magnum cartridge, aka .243 WSSM.

Announced in 2002, the .243 WSSM was intended to deliver a new level of long-range performance and accuracy to the .243 chamberings. Cartridge overall length is 2.36 inches, a half-inch shorter than the 2.8-inch length of other short-action cartridges. The .243 WSSM appears in super-short rifle actions, which should improve receiver stiffness and accuracy. The Browning Super Short Magnum A-Bolt, which weighs 6 pounds and uses a shorter action for the 2.36-inch length cartridge, and Winchester's Super Short Magnum Model 70 are currently the only factory-new products available in this round.

General Comments

The .243 WSSM case does not employ a belt; it headspaces on the case shoulder. For efficient and consistent powder burning, it retains the short-fat cartridge case geometry of the Winchester Short Magnum line. Cartridges were initially available in three bullet types: 55-grain Ballistic Silvertip, 95-grain Ballistic Silvertip and 100-grain Power Point, but only the two heavy weights have survived. The .243 WSSM shares the same basic cartridge case with the .223 WSSM, also announced in 2002. Like its small-diameter brother, it is suitable for long-range varmint shooting and for light, thin-skinned game—a good combination cartridge with light recoil.

The .243 WSSM is a fine cartridge, but it appears that all of the Winchester Super Short Magnum cartridges have peaked in terms of interest and availability. 

.243 WSSM Load Data/Factory Ballistics

Bullet (grains/type)	Powder	Grains	Velocity	Energy	Source/Comments
58 Hornady V-Max	BL-C(2)	49.2	4,068	2,129	Hodgdon
70 Nosler Ballistic Tip	IMR4320	45.0	3,663	2,083	Hodgdon
80 Sierra SBT	H414	48.0	3,514	2,191	Hodgdon
90 Swift Scirocco	IMR7828	48.5	3,280	2,148	Hodgdon
100 Speer BTXP	Supreme 780	50.0	3,117	2,155	Hodgdon
95 BST	FL	–	3,250	2,258	Winchester SBST243SSA
100 PP	FL	–	3,110	2,147	Winchester X243WSS

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

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