These top-quality firing pins are precision turned from heat-treated steel and are the proper weight for positive ignition with heavy duty springs and any type primer. Pin diameter of .090". Minor fitting may be required.Notes: The average diameter of a 1911 .45 caliber firing pins is .095"-.096" at tip. The Average diameter of 1911 .38 Super and 9mm caliber firing pins is .070"-.071" at tip. If the firing pin caliber needed is not known, check the hole size in the recoil face to determine the caliber firing pin needed for your slide before ordering.Will not fit Springfield Armory 1911's.