AFTE Store - Subclass Characteristics in Extractor Groove of Winchester Cartridges

Winchester cartridges may have a subclass striation pattern in the extractor groove. These remarkable striation patterns
have been found on Winchester 40 S&W caliber evidence cartridges and 45 Auto caliber cartridges from the NYPD Police
Laboratory ammunition supply. This phenomenon only appears once in the extractor grooves on each of these cartridges. In
some cases, the quantitative consecutively matching striae (QCMS) criteria can be used to identify these cartridges to each
other and to the parent tool/machine that caused them, but not to a firearm.

Full Journal: AFTE Journal Vol 48 No 1 (2016)