{HEAD ~ The apparatus} compensates for equipment errors that prevent a marksmanship device from providing an accurate indication of {TAIL ~ a firearm hit} or miss 
{ HEAD ~ The apparatus } compensates for equipment errors that prevent a marksmanship device from providing an accurate indication of { TAIL ~ a firearm hit } or miss
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH