I'd check it over myself before sending it back to Ruger, might be something very simple to fix. If it ends up being something else send it back to Ruger. If it's a firing Pin you'll have to send it back anyway since Ruger will not sell firing pins to anyone and the only aftermarket option is the Glend Arms pin which has mixed reviews at best. Pull the trigger group and give it a good thorough cleaning as well as the bolt. Sounds like maybe you've got something in the trigger group, I'm thinking maybe a primer came out of a case and dropped in there. What kind of ammo were you using at the time?