As I’ve said, I only war game the Western Desert November to December 1941 (Operation Crusader). I don’t know enough, or wish to pass comment about other theatres and periods.
In the desert a typical British shoot at non fixed positions was five rounds from each gun in quick succession. During operation Crusader 25pdrs (the mainstay) had front line ammunition of 112 rounds per gun, about a sixth of which was AP. Rapid fire was 4-5 rounds a minute, normal was 3. Although barrages could be hours long this rarely happened except at the start of an offensive against known fixed positions. Once the guns started to move, and they frequently had to in the fluid battles of Operation Crusader, where the ‘front’ frequently moved 30 miles a day, ammunition was always a limiting factor. Front line artillery rarely had its full ammunition quota at the start of any given day.
When firing long barrages rates of fire were drastically reduced to reduce over heating and to conserve ammunition – one or two rounds a minute from a 25pdr battery could be maintained for several hours. Medium artillery (6″ how) usually fired a round every two or three minutes in such barrages, heavy one every four to eight minutes. However, I’m not sure that this is the kind of barrage we are talking about. They tended to be coming to an end as attacks went in and were very rarely, if ever, used to stop one once it had started.
In a battle situation [war game] I think we are talking about the short sharp targeted types of fire missions rather than sustained preliminary bombardments that were designed to sap the will of the defender and denude his defences over a period of time.
My whoring and daubing: