I had the same issue (almost) and found that my spring was not properly seated. (captive)Check to see that the recoil spring is seated all the way back onto the recoil rod.
Clean and oil gun like Ruger SR22 Video shows (go to Ruger SR22 site => Ruger® SR22® Rimfire Pistol Extras watch Disassembly/reassembly video for proper way.
Shoot and have fun
Hi Jon pthat's werid all my Ruger rimfires live on Federal bulk Walmart with out any problems. Strangemy sr22p runs perfect with winchester white box bulk, but wont work with fed 550 bulk. my 10/22 LITE is the opposite, go figure!!