Can't run 22lr in a 22WMR chamber - the LR is a heeled bullet, such that the case and bullet are the same diameter, the WMR is a typical crimped bullet, where the case is larger diameter than the bullet/bore, which leaves the 22LR case undersized for the 22WMR chamber.

It'll fire, but you'll get lots of split cases, and lots of torching in your chambers.

I also can't imagine feeding function would be reliable for a 22lr to strip out of a 22WMR magazine. They'd be standing straight up before they ever reach the chamber.

Not entirely sure how you modify a blowback action to tolerate a WMR but still cycle under a LR. As much trouble as manufacturers have had figuring out the 17HMR in a semiauto, I have a hard time believing they figured out how to make a 22LR and WMR run with the same springs.

I'd venture that it was a misprint - same action was able to support both rounds for different models - but I can't imagine anybody being foolish enough to recommend such a beast, let alone making it work for feeding and reliability.

If you find it, I'll be excited to see it.