In 2003, with inspiration from high-velocity benchrest cartridges like the 6mm BR and 22 PPC, the 223 and 243 Winchester Super Short Magnums (WSSM) were introduced. Once again (for many of us), the way we hunted, shot and perceived magnum calibers changed. These calibers took the groundbreaking short magnum concept — which originated with the 300 Winchester Short Magnum — one step further, becoming the hottest, highest velocity production cartridges available.
The impressive speeds of the WSSM are achieved by putting a lightweight bullet on top of a short, fat, high-volume case. This basic concept resulted in muzzle velocities of approximately 4,000 fps with the 223 WSSM with some loadings and over 4,000 fps with the 55 gr Ballistic Tip in the 243 WSSM loads.
What are the main reasons for this performance?
- The short, fat shape of the WSSM cartridges produce a more uniform powder burn, providing consistent shot to shot velocity and better accuracy.
- Also, because the burn is so efficient, a shorter, stiffer 22" barrel can be used and still achieve high velocities.
- With most WSSM-chambered rifles, the action was also super short which resulted in a very tight, stable receiver, which some believe increases accuracy. The shorter receiver also reduces overall weight which is why WSSM calibers often make very versatile mountain rifles.
The super short receiver. To ensure feeding reliability, the WSSM cartridges, with their short 2.36" overall length, necessitate a shorter action. Because of this, a super-short action size was designed for the Browning's A-Bolt II rifle. The super-short action is not only shorter; it’s also stiffer, quicker to cycle and lighter. This allows WSSM rifles an accuracy advantage, plus they come to the shoulder quicker and with a lighter barrel overall weight is reduced so they are easier to carry.
Where can I find WSSM rifles today. Currently the WSSM caliber line is not in production in any Browning rifle. Read the side-bar on this page for an explanation. Although not as commonly found as in the years when they were originally announced, they still remain popular with devoted hunters who appreciate the advantages of a flatter trajectory. And clearly, the performance speaks for itself as much today as it did over a decade ago.