A Prize of Arms

A Prize of Arms is a 1962 British crime film directed by Cliff Owen and starring Stanley Baker, Helmut Schmid, Patrick Magee and Tom Bell with early appearances by several actors including Fulton Mackay, Tom Adams and Rodney Bewes. Set in 1956, the film follows a criminal gang as it tries to rob an army pay convoy during the Suez Crisis.

The gang enters an army barracks, disguised as soldiers and proceeds to the pay corps headquarters where, under the guise of maintenance work, they make sure that the alarms are disabled which will give them time to make their escape once the robbery takes place.For the rest of the day they try to integrate themselves into the workings of the base, including being vaccinated for Overseas service, to avoid attracting attention. As night falls, they change into military police uniforms and head for the pay headquarters again, announcing on arrival that they have had reports of a fire. They begin searching the rooms. ........

Source: Wikipedia