My 597 has been great. I've never had any feeding issues, and its fairly accurate. I have installed the Volquartsen hammer, and that helped a lot.
Remington went through three iterations for the magazines on the 597. The 3rd generation ones work well. The plastic ones suck, so toss them.
This site (Model 597 - RimfireCentral.com Forums
) has lots of good information about getting them to shoot well.
Things I would check (aside from the magazine), are the guide rods (they should only be snugged up, not tightened), and the barrel screw (make sure its not pushing against the barrel). After that I would make sure you clean the barrel really well.
Mine likes the Wolf MT, and CCI minimags.