A nail spacing verification assembly is provided which enables the spacing between nails contained in a collated nail strip, the collated nail strip advancing down a nail loading assembly of a nail gun, to be verified before the nail is allowed to advance. A first and second probe are operationally coupled with each other. If nail spacing is correct, the first probe engages the second probe causing both probes to rotate and the nail to pass. If spacing is incorrect, the first probe does not engage the second probe and the nail is hindered from advancing down a nail loading assembly.