tip 82 of reduced diameter and three enlarged diameter shoulders 84 86 88 a compression spring 90 extends around the front portion of the pin bearing against the foremost shoulder 84 so as to urge the firing pin rearward the rearmost shoulder 88 limits rearward movement of the firing pin by engaging a surface on the body the middle shoulder 86 is provided to interact with a blocking cup 90 that prevents the firing pin from moving under certain conditions described below the rear end of the pin is in the path of the upper end of the hammer 100 the firing pin is driven forward into an ammunition round in the chamber by the hammer when the trigger is pulled and all safeties are off the blocking cup 90 has a lower small diameter portion 92 and an upper large diameter portion 94 a coil spring 96 inside the upper portion urges the cup downward toward a safe position where the larger diameter portion lies in the path of the middle shoulder 86 on the firing pin with the cup in this position the pin cannot strike the ammunition round even if the hammer falls against the pin the cup is lifting by a cup release lever 98 having a pivot pin mounting to the hammer housing the hammer 100 is supported in a hammer housing 102 on a pivot pin 104 about which it oscillates between safe and cocked.