I had high hopes for these stubby little WSSM cartridges when they first came out. In fact, I went out and bought a Winchester Model 70 in .223 WSSM many years ago with the thought of re-barreling to a .243 WSSM when the OEM barrel was shot out.
The cartridges were rushed into production before being completely tested, so that the firearms division could get their rifles on the market fast. Most of us did not realize at the time that Winchester firearms was on its last gasp of breath. The quality of firearms coming out of their factories were spotty at best. Rifles initially chambered in the WSSM had some feeding and chambering problems (due to fat necks of cases). These problems were eventually overcome, but not before grumblings began to ripple through the ranks of unhappy consumers. A bigger problem was the Winchester rifles. Some were good quality, while others were just crap. Like many other Winchester rifles of that era, my .223 WSSM had accuracy issues from the start. After restocking and bedding the action and a trigger job (read: $$$$), I finally gave up and sent the rifle back to Winchester to have the barrel checked out. Everything else had been eliminated but the barrel. So I asked them to fix and/or replace the barrel.
I was shocked when I got a call from their repair shop stating that they no longer repaired rifles with the WSSM chamberings. The technician went on to explain that they had encountered too many problems with the WSSM and had made the decision to discontinue the line. He pointed out that neither Winchester nor Browning (both owned by FN) offered a rifle in the WWSM chamberings anymore. The only options offered to me by the repair shop was the return of the rifle with no work done and live with the huge accuracy problem, or I could be given full retail credit towards a new Winchester or Browning product also bought at full retail price. I eventually chose a new Browning A-Bolt rifle in 300 Win Mag.
At present, I am not aware of a single major rifle manufacturer that produces a rifle in any of the WSSM cartridges. It is a shame - because they had great potential. I hope that some manufacturer picks up the cause and breathes new life into them. I should probably note that Browning rifles never seemed to have the accuracy issues with their WSSM rifles like Winchester did. But then, Browning rifles tend to be very accurate right out of the box. Additionally, the new Winchester rifles being produced under the new ownership of FN appear to be of much higher quality.
If you currently have an accurate WWSM rifle - hang on to it. And be sure to lay on a large amount of brass. Something tells me it will be harder to find, or much more expensive to buy the brass as the years go by.