Since 1997, HomeTips has guided millions of homeowners with original, expert advice for DIY home improvement and repair. Founder Don Vandervort, a nationally recognized authority, has written more than 30 books and countless magazine articles, been a host on HGTV, and served as MSN's home improvement expert. MORE
The chances are good that the bolt is having a hard time finding the throat in the strike plate. Be sure the strike plate is secure and is in reasonable alignment with the bolt. You can file the edges of the strike plate a little, and even slightly round the edges of the deadbolt's end. If this doesn't work, you'll probably have to remove the strike plate, fill the screw holes with glue and wood matchsticks, reposition it properly, and re-screw it.