Originally Posted by
Steve M1911A1
Yes.
The "half-cock" notch on a M1911's hammer is not an active safety. That is, you are not supposed to set the gun's sear into that half-cock notch and then consider it safe. It wouldn't be.
The 1911's half-cock notch is there to catch a falling hammer, should it slip off, or be knocked off, of the full-cock notch for any reason. This had its origin with the use of the 1911 in the horse cavalry.
If I remember correctly, from an original M1911 horse-cavalry manual that I once read, the cavalry was originally supposed to carry the 1911 in "condition two," hammer down on a loaded chamber, and troopers were supposed to thumb-cock preliminary to full presentation from the holster. The half-cock notch was there to catch a thumb-slipped hammer.