Most gun manufacturers will warranty their guns for at least a year. Sometimes 2 years, and sometimes for life. A lifetime warranty was one of the selling points for buying a very expensive HK hand gun. However, you must consider what it will cost to use that warranty.

Unfortunately, federal law requires that hand guns being shipped by non-FFL holders must be send over-night mail. That will cost at least $25 if your destination is close. If not, you could end up paying $100 (Alaska & Hawaii) just to get it back to the manufacturer. If your LGS (local gun store) will ship it back for you they are permitted to use ground service. This is only allowable from an FFL holder to another FFL holder like a gun manufacturer. More than a few times I have bought the $8 dollar spring with $4 shipping. Sure it cost me $12 but it beats spending at least $25 to send the gun back.

However, many gun manufacturers will also send you the specific part if you explain the problem and they feel you know what you are talking about. Both solutions assumes you are mechanically inclined and can perform the repair yourself. If you have something drastic happen like a cracked frame or malfunction which can't be diagnosed, you will have no choice but to send it in.

A friend of mine purchases a used Berretta PX4 compact. Several times she had light primer strikes which would not allow the gun to fire. Sometimes on the second stike the gun would fire, other times not. I could not figure out the exact cause, neither could anyone who worked there, or the gunsmith. They sent the gun back to Berretta and surprisingly, they gave her an entirely new gun. So under some circumstances it behooves you to send it back...