Mandatory Credit: Photo by Imageplotter/REX (10267160n) The cartridges are collected. A 103 round gun salute by the Honourable Artillery Company at HM Tower of London is fired at midday. The 103 rounds are: 41 to mark 66 years since HM The Queen's coronation, 41 to mark the state visit of the President of the United States, and 21 for the City of London. US President Donald Trump state visit to London, UK - 03 Jun 2019