Half cock on a 1911 pistol is designed to "catch" that hammer if the sear breaks to keep the gun from going "full auto". Although some people do, a 1911 should NEVER be caried with the trigger on half cock. Most 1911 models have the half cock feature, although a few changes are out there, like the series 80 colts which have what they call a "safety shelf" instead of half cock. A true 1911 should be carried "cocked and locked". That's how it was designed to work, that's when it is at its best. Good luck.