.25 WSSM

.25 WSSM
25 WSSM cartridges loaded for an AR-15 magazine. For comparison, a 2 3/4" shotgun shell & 5.56mm NATO cartridge are included
Type	Rifle
Place of origin	USA
Production history
Designer	Browning / Winchester
Manufacturer	Winchester
Produced	2004
Specifications
Parent case	.300 WSM
Bullet diameter	.257 in (6.5 mm)
Neck diameter	.305 in (7.7 mm)
Shoulder diameter	.544 in (13.8 mm)
Base diameter	.555 in (14.1 mm)
Rim diameter	.535 in (13.6 mm)
Rim thickness	.054 in (1.4 mm)
Case length	1.670 in (42.4 mm)
Overall length	2.36 in (60 mm)
Primer type	large rifle
Ballistic performance
Bullet mass/type Velocity Energy 75 gr (5 g) VMax 3,775 ft/s (1,151 m/s) 2,374 ft·lbf (3,219 J) 85 gr (6 g) BT 3,547 ft/s (1,081 m/s) 2,375 ft·lbf (3,220 J) 100 gr (6 g) BT 3,264 ft/s (995 m/s) 2,366 ft·lbf (3,208 J) 115 gr (7 g) BT 2,999 ft/s (914 m/s) 2,297 ft·lbf (3,114 J) 120 gr (8 g) SP 2,985 ft/s (910 m/s) 2,375 ft·lbf (3,220 J)
Source(s): Hodgdon Online Reload Data

The .25 Winchester Super Short Magnum is a third member of the Winchester Super Short Magnum (WSSM) cartridge family created by Winchester and Browning. It is the largest caliber of the WSSM's and is the most capable of handling large game such as deer and wild boar.

It is a necked-up version of the .243 WSSM, which is in turn a shortened .300 WSM (Winchester Short Magnum). The WSSM cartridges are based on ballistics design philosophies that are intended to produce a high level of efficiency.

Like other WSSM cases, the .25 is short and fat, which is designed to be more efficient.

Unlike the other WSSM rounds, the .25 is a magnum in name only, based on the case it uses. Performance wise it is a clone of the .25-06 Remington, making it well suited for medium to large game. The 25 WSSM provides the same performance as the 25-06 Remington, with the advantage of having lighter short action rifles. Having the short fat design, the cartridge loads burn at a more consistent rate, providing a higher level of accuracy. Performance is far less than other .25 caliber magnum rounds as the .257 Weatherby Magnum. In fact, ballistically it's almost identical to the improved version of the .257 Roberts, which P.O. Ackley said was his favorite choice for an all-around cartridge.