Handguns

Glock 17

Miu Miu uses a Glock 17 pistol in Episode 24 ("Jailbreak..."). It appears to be a 3rd Generation model as indicated by the finger grooves and accessory rail (the latter of which in some frames appears to disappear or become simplified). Miu Miu fires her Glock twice; four consecutive shots are fired the first time and then later on nine rounds (while nine gunshots are heard here, ten bullets are shown in the still frame that follows the moment the Glock is fired) Interestingly, Miu Miu's Glock runs empty after only firing it a total of 13 times despite standard Glock 17 magazines holding a maximum of 17 rounds. The Glock 17 also appears to be the main service pistol for the Green Dolphin Street Prison security force, as many guards are seen armed with Glock pistols throughout the season.

3rd Generation Glock 17 - 9x19mm. Note the finger grooves, thumb reliefs, and accessory rail on the frame, which differentiate it from the older model

Miu Miu aims her Glock 17.

Miu Miu's Glock, smoke flowing from the recently fired barrel.

Miu Miu brandishing her Glock 17.

A closeup shot of the pistol.

Firing the Glock.

13 rounds later, Miu Miu's Glock is empty as shown by the locked back slide. Considering that Miu Miu is the chief prison guard in this setting, she should be expected not to underload her 17-round Glock magazine with only 13 cartridges.

Another shot of the supposedly empty Glock. However, it can be clearly seen that there is at least one round loaded in the magazine as shown through the open ejection port which wouldn't make sense if the gun had previously run empty. Miu Miu does not reload her sidearm.

Miu Miu's Glock after her being disarmed from it. The visible accessory rail and finger grooves clearly identify this as a 3rd Generation model.

A swarm of security guards, armed with either Ithaca 37 shotguns or Glock-style pistols, although the latters' illustrations are too simplified to make out a specific model but it is safe to assume that their issued sidearm is a 9mm Glock.

Lafaucheux Revolver

In Episode 26 ("Bohemian Rhapsody, Part 2"), Weather Report after encountering a manifestation of Vincent van Gogh from one of his self portraits, snatches a razor blade from him which turns into a paint brush and then subsequently, a Lefaucheux revolver which closely resembles the real one believed to have been used by van Gogh to end his own life.

Lefaucheux pinfire pocket revolver

Weather Report, shocked at the discovery that the paintbrush in his hand has transformed into the cause of a 7mm bullet head wound.

The Lefaucheux lying on a drain cover.

A closeup shot of the revolver.

Ditto, different angle.

Shotguns

Ithaca 37

Dark-toned Ithaca 37 shotguns with black synthetic furniture appears in the hands of prison guards in various episodes, including Episode 20 ("The Witness").

Ithaca 37 Riot Version - 12 gauge

Two of the security guards on an airboat ready their shotguns in Ep.20. The Model 37s appear to be slightly oversized in this frame.

In the same episode, another guard shows his trigger discipline while handling the Ithaca 37.

A guard in Ep.23 ("Jail House Lock!") holding his Ithaca.

Machine Guns

Browning M2

In Episode 20 ("The Witness"), M2 Browning machine guns are seen mounted on prison guard airboats. The MGs are correctly referred to as "12.7mm M2s" by Narciso Anasui.