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.223 Winchester Super Short Magnum (WSSM)

History

Introduced in 2003 the .223 and .243 WSSM cartridges were created by Winchester as an attempt to inspire shooters interests in the latest ballistics technology. During the design phase of the .223 WSSM, it was found that the original 1:12 twist rate would not stabilize the 64 grain PowerPoint bullet. To remedy this problem, Winchester adopted a 1:10 twist rate, ideal for a variety of heavy .224 caliber projectiles.

Initially the .223 WSSM was well received and rifle sales remained steady. In 2004 Winchester released the .25 WSSM, then in 2006, the company folded. Rifles for the .223 and .243 Winchester are currently advertised as being available from Browning however future availability is difficult to determine. A thorough explanation of the collapse of Winchester rifle production can be found in the .25 WSSM history text.

Performance

Although the case design of the .223 WSSM is radically different from traditional cartridges, performance is much the same as other ultra velocity .224’s such as the .220 Swift, .22-250 and .22-243. All of these cartridges are capable of pushing .224” projectiles at speeds exceeding 4000fps and all are capable of outstanding accuracy when fired from a suitable platform.

Factory Ammunition

Regardless of the collapse of the Winchester trademark, Olin continue to produce Winchester brand factory ammunition for the .223 WSSM. Factory loads include a 55 grain soft point at 3850fps, the 55 grain Ballistic Silvertip also at 3850fps and the 64 grain Power Point soft point bullet at 3600fps. In sporting rifles, a loss of 70fps is common in comparison to Olin’s test barrel results.

While both of Olin’s 55 grain loads are designed for varminting, the 64 grain load is designed for use on light medium game in localities where .22 centerfires are legal. In most states of the U.S, it is illegal to use the .223 WSSM on medium game. This bullet is best suited to game weighing 40kg (88lb) and up to 60kg (130lb) as a safe maximum.

Hand Loading

With 55 grain projectiles the .223 WSSM produces optimum results when loaded with powders in the 4064/ Varget range. Projectiles of 60 grains and above achieve excellent results with medium slow burning powders such as IMR 4350. Safe working velocities from a 24” barrel include 4000fps with 50 grain projectiles, 3900fps with 55 grain bullets and 3750fps with 60 grain bullets. Further notes on hand loaded bullet performance can be found throughout the related .224” caliber pages of this knowledge base.

Closing Comments

The .223 WSSM is certainly a radical design. Both the cartridge and Winchester rifles have gained a small but staunch fan base among varminters. At this stage it is unlikely that the WSSM’s will survive as mainstream rifle caliber offerings. Nevertheless, reamers can be obtained for shooters wishing to build custom rifles and experiment with this cartridge.

Suggested loads: .223 WSSM					Barrel length: 22”
No	ID		Sectional Density	Ballistic Coefficient	Observed MV Fps	ME Ft-lb’s
1	FL	64gr Winchester PP	.182	.233	3500	1741
2	HL	53gr Barnes TSX	.151	.231	3900	1776
3	HL	55gr FMJ	.157	.272	3900	1857
4	HL	60gr Nosler Partition	.171	.228	3750	1873

Suggested sight settings and bullet paths
1	Yards	100	150	237	275	300	350
	Bt. path	+1.7	+2	0	-2	-4	-8.5
2	Yards	100	150	256	296	350	400
	Bt. path	+1.6	+2	0	-2	-6	-11.5
3	Yards	100	150	267	310	350	400
	Bt. path	+1.5	+2	0	-2	-5	-9
4	Yards	100	150	251	291	350	400
	Bt. path	+1.6	+2	0	-2	-6.6	-12