The C-clip that retains the recoil springs on the guide rod broke, during use. (My fault, I tweaked it a bit, during the previous cleaning.
The spring made its way between the slide and guide rod, and the washer behind the clip got bent. Everything got jammed with about 1.5 inches of spring sticking out the front of the pistol.
It took about 10 minutes to wiggle, jiggle, and work the slide to the point that I could get the live round out of the chamber. Once home, it only too a couple minutes to get it torn down. But, it took about 3 weeks to get a replacement retaining clip and washer. Now, I keep a few on-hand, even though the replacement has never failed. (And, I think Ruger eliminated the washer when they went to the revised safety mechanism, but I'm not positive.)