Factual error: In the last British battle at Omdurman near the end of the film, the British bugler is shown wearing a Pattern 1903 bandoleer - not made until well after the film is set.
Factual error: When Kitchener is shown inspecting Harry's old regiment, one group of African or Egyptian troops is shown to be wearing the Pattern 1914 Infantry Equipment, not made until 1914 at the earliest. Additionally, it has the 1918 modification to have two closing straps, so is over 20 years too late for the 1894 date at that point.