Mark II was introduced in 1871 using the simpler and cheaper "Fraser" gun construction method which had proved successful with the RML 9-inch 12-ton Mk IV gun.

[4] In 1874 the process of development made a "New Eighty-one Ton Gun" available in Woolwich.

Sometime after 1878, "attached gas-checks" were fitted to the bases of the studded shells, reducing wear on the guns and improving their range and accuracy.

Subsequently, "automatic gas-checks" were developed which could rotate shells, allowing the deployment of a new range of studless ammunition.

Thus, any particular gun potentially operated with a mix of studded and studless ammunition.