At the beginning of the film, two gold-plated Desert Eagle Mark XIXs are dual-wielded by Hollywood (Sung Kang) and like your typical Hollywood guns, they manage to fire off much more than what the magazine can hold.
Glock 26
Ryan Maslow (Ben Miles) gives Mika Coretti (Naomie Harris) a Glock 26 for protection of herself. Ryan mentions that the gun is clean and it has no serial numbers. Mika uses the Glock throughout the rest of the film, until the Ozunu base raid, when she wields a Beretta Cougar.
Glock 19
Due to a continuity error, the Glock 26 used by Mika Coretti (Naomie Harris) changes to a Glock 19 when she escapes the Europol warehouse.
SIG-Sauer P228
The SIG-Sauer P228 appears as the standard issue sidearm to Europol agents. Most noticeable seen during the arrest of Raizo (Rain).
Unknown SIG-Sauer pistol
At the beginning of the film, one of Hollywood's Yakuza thugs is briefly seen grabbing a SIG-Sauer pistol from his waist before getting killed by a ninja. It could be either a P220 or a P226, but it's not seen clearly enough to determine it from the single/double-stack bulges or the barrel size.
A Heckler & Koch USP is used by Ryan Maslow (Ben Miles) as his sidearm throughout the film. Another one is also seen in the hands of a Europol agent guarding Raizo (Rain) during the warehouse shootout.
Tokarev TT-33
A Tokarev TT-33 can be seen in the hand of the former KGB agent Aleksei Sabatin (Wladimir Tarasjanz) during the flashback of his wife. The TT-33 is anachronistic as the KGB used Makarov PMs.
Submachine Guns
Heckler & Koch MP5A3
Heckler & Koch MP5A3s are used by a majority of Europol agents. The weapons are usually seen fitted with mid-range sniper scopes.
Heckler & Koch MP5K
A Europol agent is briefly seen with a Heckler & Koch MP5K with an Aimpoint sight during the arrest of Raizo (Rain). Ryan Maslow (Ben Miles) also uses a plain MP5K during the Ozunu base raid, most notably to fire at Takeshi (Rick Yune). His MP5K features the Navy trigger group.
Heckler & Koch SP89
At the beginning of the film, some of the Yakuza thugs carry Heckler & Koch SP89 submachine guns converted to full-auto and loaded with 30-round magazines.
Micro Uzi
At the beginning of the film, Micro Uzis can be seen in the hands of several of Hollywood's Yakuza thugs.
Shotguns
Mossberg 500 Cruiser
At the beginning of the film, a Mossberg 500 Cruiser with extended magazine tube is seen in the hands of a Yakuza, but gets killed by the ninja's kusarigama before he can use it.
Franchi SPAS-12
A Franchi SPAS-12 is briefly seen in the hands of a Europol agent during the warehouse shootout. He briefly gets to fire it before his death. Its appearance is very brief and shaky, so screencaps are hard to get.
Rifles / Carbines
Heckler & Koch G36
The Heckler & Koch G36 rifles are used by several Europol agents throughout the film. Most noticeably during the warehouse shootout and the Ozunu base raid. The weapons are usually seen fitted with ZF 3x4° dual optical sights and tactical flashlights.
Heckler & Koch G36K
The Heckler & Koch G36K rifles are also used by several Europol agents throughout the film. The weapons are mostly seen fitted with ZF 3x4° dual optical sights and tactical flashlights. Some people might get the longer G36 and the G36K mixed up in this film, but this is understandable, since most are seen very briefly or in poor lighting conditions.
Machine Guns
FN MAG
FN MAG machine guns are mounted on Europol Humvee and APC vehicles during the raid on the Ozunu base.
Launchers & Explosives
CAW 40mm Grenade Launcher
An Airsoft CAW 40mm Grenade Launcher is seen in the hands of a Europol agent launching flares during the raid on the Ozunu base.
M72 LAW
M72 LAWs are used by Europol agents during the Ozunu base raid.
M67 Hand Grenade
An M67 Hand Grenade can be briefly seen during the Ozunu base raid. A Europol agent uses it to clear a room of ninjas. It can be easily identified by its shape.
Others
Fictional Taser (Umarex Walther Red Hawk)
During the arrest of Raizo (Rain), Europol agents are seen using fictional Tasers. The weapons are actually based on an Umarex Walther Red Hawk (a CO2 powered air pistol with an integral red-dot sight) fitted with a barrel extension resembling a Taser cartridge.