Although the .303 ball Mark VII is always known as having a 174 grain bullet, the original Mark VII adopted in March 1910 had a 160 grain bullet. The earlier bullet had a longer aluminium tip filler and no cannelure.
In August 1910 a newly made batch failed accuracy proof and production was suspended. A new design to RL 17069 was adopted and approved in November 1910 as the now familiar 174 grn bullet. The Mark VII designation was not advanced, probably to avoid embarrassing questions in the press and parliament.
Yesterday I pulled a Greenwood & Batley 1913 dated Mark VII for a totally different reason and to my delight found an uncannelured bullet. Weighing confirmed it was a 160 grain bullet, and even better the base was stamped “GB 7”.
Although this is after the introduction of the 174 grain bullet, it seems G & B used up stocks on hand of the 160 grain. I knew from someone else that these G & B 160 grain loads existed but this is the first one I have found.