Mk. VII was THE standard .303 round from about 1912 until the 7.62 Nato was adopted. I have a few Mk.7 cordite rounds left, RL 1954. Also several Mk.7 DA 1950 vintage, also cordite. VIIz and VIIIz were mostly for machineguns. All of the bullets I've taken apart had aluminum tips, never seen a plastic one. Some of the Canadian ones had rather lopsided jackets. I have quite a bit of .303 Mk.VII MH 1941 (Footscray, Australia) but it all hangfires. Smells nice when it goes off though! Recently several "experts" said the cartridge on the map in the "Paschendaele" movie should have been a round nose Mk. VI. Not so! DA was loading Mk.VII at least as early as 1915, if not before.