Wall gun

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.

German wall guns (below) and muskets (above).
Long matchlock firearm requiring a rest, 16th century, Ming dynasty
Chinese firing a gingal.