Possibly based on real but not sure weapons:

Pistol

The Pistol.

Holding a Pistol.

The player character somehow ejects the magazine by fiddling with the Slide.

Inserting a fresh magazine.

Chambering the weapon.

Holding Dual Pistols, the left hand is unanimated and clips through the gun when not firing/reloading/aiming.

Reloading Dual Pistols.

Commando Rifle

The Commando Rifle is an alternative assault rifle that can be fitted with a scope and a "Flash" attachment located under the barrel that blinds opponents with a bright light.

An unscoped Commando Rifle.

Holding a scoped Commando Rifle while looking at an NPC holding a "modernized" version of the WW1 Machine Gun inspired Assault Rifle from Iron Storm that functions as the basic assault rifle.

Reloading a scoped Commando Rifle via pulling the charging handle to eject the magazine.

Inserting a new magazine into the Commando Rifle.

An NPC holds a Commando Rifle in a Black Out Saigon cutscene.

Sniper Rifle

The "Sniper Rifle" looks an advanced version of the "Dragunov Snayperskaya sniper rifle" from Iron Storm, linking the two games.

Holding the Sniper Rifle, the cheapest version lacks a scope.

Holding the Sniper Rifle, with a scope this time.

Using the bolt after firing.

Changing the magazine.

A "James Anderson" with his Sniper Rifle as a BOS opponent in Black Out Saigon as a reference to Iron Storm's protagonist with the same name who also used the weapon.

"Intensive Care"

The "Intensive Care" is a missile weapon introduced in the expansions, it can be upgraded with a scope and is the most damaging weapon in the game, being capable of destroying exoskeletons far faster than other weaponry.