Counter Revolutionary Warfare wing on the range with suppressed MAC 10s and Sterling L34A1s. Photo was likely early to mid 70s before the adoption of the H&K MP5 in 1977.
SAS Troopers conducting rehearsals for the Balcombe St siege. The H&K MP5 wasn't issued until the late 70’s. Before that they used the Ingram MAC 10 which had a cyclic rate of 1300 RPM.
The Balcombe Street siege was an incident involving members of the Provisional Irish Republican Army (IRA) and London's Metropolitan Police lasting from 6 to 12 December 1975. The siege ended with the surrender of the four IRA members and the release of their two hostages. The events were televised and watched by millions.