.243 Winchester Super Short Magnum

Winchester has discontinued the manufacture of 243 WSSM ammunition. The product is only manufactured periodically, often at inconsistent intervals.

• Name — 243 WSSM • Origin — USA • Type — Rifle • Designer — Browning / Winchester • Design Date — 2003 • Manufacturer — Winchester • Production Date — 2003–present • Parent —.300 WSM • Case Type — Rimless, bottleneck • Bullet —.243 • Land —.237 • Neck —.291 • Shoulder —.544 • Base —.555 • Rim Dia —.535 • Rim Thick —.054 • Case Length — 1.670 • Length — 2.362 • Rifling — 1- • Primer — Large rifle • Bw1 — 58 • Btype1 — VMax • Vel1 — 4068 • En1 — 2132 • Bw2 — 70 • Btype2 — BT • Vel2 — 3707 • En2 — 2136 • Bw3 — 80 • Btype3 — BTSP • Vel3 — 3545 • En3 — 2233 • Bw4 — 90 • Btype4 — SFT • Vel4 — 3280 • En4 — 2151 • Bw5 — 100 • Btype5 — BTSP • Vel5 — 3136 • En5 — 2184 • Balsrc — Hodgdon

The.243 WSSM is an addition to the Winchester Super Short Magnum (WSSM) family of cartridges, which also include the.223 WSSM and the.25 WSSM, and the idea behind the.243 WSSM was to develop a compact, higher velocity version of the well-established and internationally popular.243 Winchester unveiled by Winchester in 1955. The.243 WSSM was first introduced in 2003. The.243 WSSM's case is unusually short and fat in profile, contrasting markedly with most other rifle cartridges, and is intended to take advantage of what ballisticians have shown is the more uniform and efficient burning of propellant powder when it is held in a short, fat stack by the cartridge case.

In their ballistics tables, Winchester list a very high muzzle velocity of 4060 ft/s with a 55 gr projectile for this cartridge. Based on Hodgdon reloading data typical velocities should range from approximately 4000 ft/s with a 58 gr bullet to approximately 3000 ft/s with a 100 gr bullet. The percentage gain in performance over the older.243 Winchester is around 10% or less. This cartridge is usually used for small game such as varminting, and used for animals as large as deer.

Compared to other factory 6mm sporting cartridges the.243 WSSM is capable of functioning in the AR-15. Other factory produced 6mm cartridges like the.243 Win and 6mm Rem are both too long for the AR-15 and require the AR-10 platform. The.243 WSSM is shorter than the.243 Win, giving the.243 WSSM the ability to fit in a super-short action rifle. Thus.243 WSSM rifles can be lighter, have stiffer actions and have faster actions to cycle. The.243 WSSM gives generally a 10% increase in velocity over the.243 Win.