Lever or Pivot Safety
Located either on the bolt or just behind the bolt handle on the frame of the receiver, it blocks the firing pin when engaged. On some firearms, the lever safety located on the bolt will have three positions. The back position (i.e., toward the shooter), does not allow the bolt to be opened, and the firearm will not fire. In the middle position, the bolt can be cycled, but the firearm cannot be fired. In the forward position, the safety is OFF, and the firearm can be fired. Other safeties feature only two positions - ON and OFF. These types of safeties are marked either with green and red dots or with an "F" for fire or an "S" for safe.
Hammer at Half-Cock Safety
This type of safety is not as common as those listed above. It is typically found among lever action and break action firearms or antique and replica firearms. In the half-cock position, the hammer does not rest on the firing pin and the trigger is locked. When the hammer is pulled all the way back into the cocked position, the firearm can be fired. Be sure to check the owner's manual as some manufacturer's firearms are only safe when the hammer is in the "fully forward" position.
IMPORTANT! Trigger must be pulled to move the hammer from FULL to HALF-COCK position. Make sure that you have full control of the hammer and that it does not slip from your grasp.