[note 2] However, the ballistic characteristics, propellant charges and shells used were similar for all Mks I–V.

Mks I–V were limited by a short range and high weight, being 4–5 tons heavier than the succeeding Mk VI which was designed as a howitzer and hence had a much lighter barrel.

The improvised nature of the design led to failures such as premature explosion and unreliability in action, and difficulties of maintenance in workshops.

[8] Despite their shortcomings they were generally considered a success : "They were monstrous things and extremely heavy, but the machinery of the guns was very simple and that's why they did so extremely well and didn't give nearly as much trouble as some of the more complicated guns that came to appear later on.

[9]They remained in use on the Western Front throughout the First World War as Britain's need for heavy artillery increased and was never fully met by production of modern equipment.