2 x 12.7mm rounds ( .50 cal ) with projectiles attached. One has been put into a tap and dye and has a threadded head, possibly for ysing as a second cocking handle on a Browning M2 MG, the other has had the base sanded to remove any markings SL 4 ? inert 400 june 94 wark vc club, ammunition, 12.7mm, m2, 50 cal, inert

QCB stands for quick change barrel and relates to a heavy Browning Machine Gun. This manual set up for training course on it's use and function.Stapled assembly A4 sheets with green cover and with 42 pages of the use, description and maintenance of a Browning 12.7mm M2 Heavy Quick Change Barrel (QCB) machine gun.Date, "November 2004" then "1/2/2005".royal navy, gunnery, book, training course