Additional concept art. You can see some examples of the mechanism which pulls rounds from the strip-feed clip (and yes I mean clip, not magazine. The cartridges are being fed from the clip mechanically, not by spring tension).

Illustration of two Endrish soldiers manning a Visscher Machine-Gun, circa 1405.

Some (rather lazily done) technical drawings of the Visscher machine gun, its clipazine, and its tripod mount.

More concept art. For the longest time, the Blikopener was going to have a side-mounted pan magazine. In the end, much of the internals of the weapon would remain identical, only the feeding mechanisms would be oriented vertically so as to accept the vertical drum magazine.

POV you've pissed off Karras while he was having a smoke (and likely with a few cups of wine in him).