tipstock
tipstock
(ˈtɪpˌstɒk)n
(Firearms, Gunnery, Ordnance & Artillery) the detachable section of a gun's handle, usually gripped by the left hand of the user
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014