Could be a broken lifter and striker(transfer bar), too. I keep a spare of each cuz they have a habit of breaking at the wrong time! Not expensive, less than $10 for both from H&R or Brownell's. If you do the work yourself, you'll want to read the trigger job links in the Centerfire forum FAQ and Help sticky. Or just send it to H&R for repair, they also may send you the parts to DIY, they've done it before.
Tim