Essentially, it was a scaled-up version of the army's standard infantry musket, operating under the same principles, but with a bore of up to one-inch (25.4 mm) calibre.
This sort of weapon may also be found described as a rampart gun, hackbut or amusette, a name originally given to early medieval hand cannon.
[2] They were equipped with a yoke at the point of balance, which tapered into a pivot, which could be inserted into several sockets along the walls, which would absorb the recoil of the piece and also provide a stable gun platform.
Some of these weapons had multiple barrels which enabled volleys to be fired much faster than a normal single-shot wall gun.
Tests showed that they were capable of hitting a sheet of common writing paper at 600 yards (550 m), but as this is comparable angular precision to that of a modern full-bore target rifle these results may be optimistic.
Bolt action wall guns firing metallic cartridges were used in India and China in the late 19th century.