Legendary Arms Works makes one, pretty much a Bansner I believe. Bansner is re-tooling for his, but doesn't appear to be including Rugers right now.
The factory synthetics are tough and cheap if you're just looking to spare your walnut in the field.
Unless they have added to their offerings lately, LAW/Bansner only produces long action Ruger stocks.
No personal experience, but if looking for lightweight, I believe Brown Precision makes a short action Ruger stocks.
