It was also fitted with a simple recoil mechanism in which the gun recoiled up a sloping ramp and ran out under gravity, but this was turned down for the same reasons.

To save money the authorities ordered old wooden SBML 9-pr carriages to be used for the Armstrong 12-prs, a step which proved to be false economy because the greater power of the new gun broke many trails near the elevating gear bed-plate. Replacement was both expensive and time consuming.

The 12-pr was the first British field gun to be fitted with a traversing gear. Unfortunately, adapting it to the old 9-pr carriages made it rather complicated - and expensive - and limited top traverse to only 1½° right and left. Still, it proved a boon to the old-time layers.