The following weapons were used in the anime series Space Dandy:
A Gogol Empire-hired mercenary uses an AK-47 assault rifle in "Sometimes You Can't Live with Dying, Baby".
Authentic AK-47 built from US Receiver. This is an Actual Screen used AK-47
from the film We Were Soldiers
(built by Cinema Weaponry) - 7.62x39mm
The beret-wearing mercenary prepares to engage a zombie.
The mercenary is surrounded by zombies. Note that the 30-round magazine in this shot is animated a bit larger than the actual magazines used for the AK-47.
Dandy somehow was able to pull a Panzerschreck (with the stock incorrectly positioned on the front...) from his back in "There's Always Tomorrow, Baby" to destroy a calendar that was responsible for maintaining the "Groundhog Day"-style time loop.
RPzB 43 "Panzerschreck" rocket launcher with rocket - 88mm.
From out of nowhere, Dandy pulls out a loaded Panzerschreck.
You can see the flip-up sight of the Panzerschreck.
"Tomorrow!" Dandy aims the Panzerschreck at the calendar.
The front part of the Panzerschreck. Note Meow and QT covering their ears to avoid being temporarily deafened by the backblast.
Sten Mk III
What appears to be a Sten Mk III is used by Dandy when he first attempts to destroy the calendar causing the groundhog loop in "There's Always Tomorrow, Baby".
Dandy prepares to raise the Sten Mk III.
The Mk III being fired to take out the calendar.
Bea uses a stainless Walther PP to gun down Dr. Gel and take out a holographic projector of Admiral Perry near the end of "Never-ending Dandy, Baby".
Nickel Walther PP Pistol - .32 ACP.
Bea pulls out a PP from his jacket.
You can see more details of the PP, such as the barrel and the heel of the magazine.
The stainless PP is fired at Dr. Gel while Bea smirks.
Bea fires the PP at a wounded Dr. Gel after the latter tries to crush him for his betrayal.