This sounds like the trigger stops needs adjusting or the sear spring might need attention. If you can field strip the gun, slide off, stocks off, with the proper size allen wrench, turn the screw inside the frame under the trigger clockwise, maybe half a turn. The lower screw, behind the trigger should be backed off a quarter turn. We used an allen wrench bent about 15 degrees to make it easier to access through the side of the frame. Cock the hammer and fire the gun. The hammer should fall completely. Hopefully it does. If so, cock the hammer again and turn the top screw up, counter clockwise, until the hammer falls. then turn clockwise a half turn. The upper screw is now set. The bottom screw now needs to be set. Turn the screw towards the trigger until the hammer will not fall when fired. Place a .015 shim between the trigger and lower screw and with the hammer cocked and pressure on the trigger, back out the lower screw until the hammer drops. Both trigger stops are now set. Hope this works. If it's the sear that is the problem that will be another story. But it's not too bad to remedy that. I'll wait to hear from you.
If you could, at the bottom of the frame at the magazine opening there is a stamp mark. what character is it?