Pino of the criminal group A Small House uses a golden derringer as his sidearm.
M1911A1
The M1911A1 is seen with Mr. D aka Borjigin Khan, most significantly in "A Consideration on "Time Limits".
SIG-Sauer P226R
The SIG-Sauer P226R is used by the Japan Safety and Promotion Company (JSPC) team when they need to use a weapon.
SIG-Sauer P230
A SIG-Sauer P230 appears to be used by Botan Neguro as her sidearm while doing JSPC operations. Given that she's in middle school, it's appropriate for her to use a compact pistol so that she can use it easily. One is seen at the end of "A Consideration on "Truth".
Smith & Wesson M&P
The Smith & Wesson M&P is used by Mickey Miller and Oliver Thornton as their sidearms, despite the fact that the CIA cannot legally operatae in American territory and be armed.
Unknown
Submachine Guns
Beretta PM12S
The Beretta PM12S is seen with Thorne Mafia soldiers in "A Consideration on "Divine Thunderbolts".
Heckler & Koch MP5K-PDW
The Heckler & Koch MP5K-PDW is seen with armed Politi Beredskapstroppen operators guarding the scene of a Tesla Crystal-related incident in "A Consideration on the "New-Fledged Spy". Una Castila terrorists are seen with it in "A Consideration on "Time Limits".
Assault Rifles
AK-tye rifles
AK-type rifles are seen with Elmo and Pino when they were training at a terrorist camp.
AK-74
The AK-74 is seen withe Black Block 49ers in "A Consideration on "Divine Thunderbolts", loaded with drum mags.
Unknown Rifles
Armed men in a foreign battlefield are seen wielding unidentified rifles due to the animation done by Gambit.
Carbines
M1 Carbine
A M1 Carbine appears to be used with child soldiers being trained in Palau under Una Castila direction in "A Consideration on "Searches".
SKS rifle
A SKS rifle (or an OP-SKS) is used by Sergei when he goes hunting or needs to defend himself against hostile animals in the North Caucasus in "A Consideration on "Dog People".
Shotguns
Remington Model 870
A Remington Model 870 with wood furniture is used by Mickey in the North Caucasus before Elmo takes it in "A Consideration on "Dog People".
A SVD Dragunov is used to shoot at Botan's direction by Pino, first seen in "A Consideration on "Relationships of Trust".
Machine Guns
Browning M2HB
Browning M2HBs on mounted stands are seen on the deck of the CIA-manned hospital ship Asclepios.
M134 Minigun
The M134 Minigun is used by Elmo in "A Consideration on "Dog People"
Phalanx CIWS
Phalanx CIWSes are seen on the deck of the CIA-manned hospital ship Asclepios.
Rocket Launchers
RPG-7
A RPG-7 is used by Elmo in "A Consideration on "Dog People" to take down the Tesla Shard-infused chimera.
Others
M2 Flamethrower
Kuruma uses a M2 Flamethrower to subdue the Tesla Shard-infused chimera in the North Caucacus near the end of "A Consideration on "Dog People". The twist is that the fuel tanks are filled with vodka and other types of alcohol in order to get the chimera to be vulnerable.