Heretofore in the pistols of this class, when the hammer was cocked ready for firing, and it became necessary to lower the hammer to the safety position without allowing it to touch the firing-pin, it required both hands of the user to accomplish this act, because the trigger had to be pulled with the first finger of the right hand to release the hammer and the grip-lever had simultaneously to be pressed into the grip to release the trigger for operation, to do this required the keeping of the thumb of the right hand in a horizontal position on the left side of the grip. Therefore it was impracticable to also extend the thumb of the right hand while this hand pressed in the grip-lever and pulled the trigger, upward so as to rest upon the thumb-piece of the hammer and, thus controlling the hammer, to gently lower the same and restrain it from falling and from striking the firing-pin, because any attempt to do this would result in loosening the necessary hold upon the grip-lever. Consequently, the lowering of the hammer had to be performed by the other hand, this is a serious drawback in a military arm, as a soldier and especially a mounted soldier does not in action have both hands free for such use. To overcome this difficulty, I have provided the grip-lever w with a projecting nose w2 in rear of its pivot, which stands closely in rear of and below the hammer when cocked, and the hammer is so fitted that it may be drawn rearward somewhat farther than to its cocked position. When the hammer is drawn fully back it strikes the nose w2 and, by pressing the same downward, it causes the grip-lever to turn on its pivot forcing the lower portion into the grip, thereby releasing the trigger. By this arrangement the thumb of the hand grasping the grip needs not to be kept at the side of the grip for pressing the grip-lever, but the thumb may be applied to the hammer and through the same operate the grip-lever to release the trigger, then the trigger may be operated with the first finger of the same hand to release the hammer and finally the thumb, still applied to the hammer, may allow the same to slowly descend to the safety position, without requiring the aid of the other hand.