1833 Ottoman seven-barrel flintlock - photo

[mklotz]

No sensible warrior could or would want to carry it in battle so, if used at all, it must have been in a fixed emplacement, perhaps a murder hole-like slit in the wall of a castle's entryway lobby. It might also have been used onboard a ship to repel boarders.

The reloading delay makes it pretty much a one-time weapon.