A slide assembly (328) capable of repeated reciprocal movement about an upper portion of a firearm having a firing pin assembly (384), including a firing probe tip (301) for selectively contacting a chambered ammunition cartridge, includes a frame having a forward end and an aft end, the frame accommodating a barrel of the firearm along a longitudinal firing axis. An ejector port is formed in the frame and has a breech face (340) against which an end cap of the ammunition cartridge abuts when in a firing position. A longitudinal firing probe bore is formed within the frame and extends from adjacent the aft end of the frame to adjacent the breech face, the firing probe bore also is in concentric alignment with the firing axis. The slide assembly further includes a probe tip bore (389) in concentric alignment with the firing axis and extending between the breech face and the firing probe bore for allowing the firing probe tip access beyond the breech face and into the ejector port. An engagement slot is formed in the firing probe bore for mating engagement with a lower key housing of the firing assembly.
