Momo (Michel Muller) also carries a Beretta Cougar Inox inside the cases of weapons he brings to Hubert. Momo also carries one alongside his SIG P226 after the arcade shootout. A Yakuza thug carries two.
It looks like they removed the return spring and the spring guide is sticking out of the front of Momo's gun. They did something similar in lord of war but took out the guide as well.
Beretta 92FS (Two-tone)
Two two-tone Beretta 92FSs are visible inside one of the suitcases Momo presents to Hubert upon his arrival in Japan.
Beretta 92FS
A Yakuza thug draws an all-black Beretta 92FS on Hubert but is quickly disarmed by a golf ball. Hubert (Jean Reno) himself carries a Beretta with a laser during the bank shootout after his Raging Bull runs out of ammunition.
Beretta 92FS Inox
A Yakuza thug holds a Beretta 92FS Inox on Hubert during the bank standoff.
Beretta Model 70
Another Japanese Intelligence agent draws his Beretta Model 70 on the Yakuza inside the bank.
Desert Eagle
A black Desert Eagle MK I is among the many weapons Momo presents to Hubert upon his arrival in Japan.
FN Browning M1905
Irene (Alexandre Brik) holds a FN Browning M1905 on the bank president before carelessly tossing it aside when he gets a hold of Hubert's Model 686. Hubert mockingly tells Irene that the M1905 looks like a device used for ear-piercing.
Glock 17
A Yakuza thug holds a Glock 17 on Hubert and is also disarmed by a golf ball.
SIG-Sauer P225
Takanawa (Yoshi Oida) draws a silenced SIG-Sauer P225 during the bank standoff but is shot by Hubert before he gets a chance to fire it.
Paris police Detective Hubert Fiorentini (Jean Reno) carries a Smith & Wesson Model 686 as his service sidearm. During his confrontation with the leader of the transvestite bank robbers, Irène (Alexandre Brik), he kicks it over to Irene without the latter knowing it has been unloaded.
A female Japanese Intelligence agent draws a Smith & Wesson Model 60 on the Yakuza inside the bank.
Smith & Wesson Model 66
Momo (Michel Muller) brings two Smith & Wesson Model 66 revolvers for Hubert including a heavily-modified model that he demonstrates for Hubert. A Japanese Intelligence officer also carries one during the bank standoff. Considering the production, the gun probably was the same used on the set of "The Transporter".
Taurus Raging Bull
Hubert (Jean Reno) picks out a Taurus Raging Bull from Momo (Michel Muller). After the bank shootout (during which the Raging Bull inexplicably made people fly across the room when they were fired upon), Momo picks up Hubert's discarded Raging Bull and waves it around at the dead Yakuza members. Hubert identifies the revolver as a ".45" when talking to Takawana, meaning that it only has a five-round capacity, but he always shoots 6 times. During the arcade shootout he fires only 6 rounds again, the last guy he kills pulls the trigger and accidentally shoots his friend above.
EDIT: These MP5s appear to be Tokyo Marui airsoft guns, like the PSG-1 seen on the background.
Mini Uzi
A Mini Uzi is visible inside one of the suitcases, which Momo describes as the "latest Uzi", firing "50 rounds per second". A Yakuza thug during the bank standoff also carries one.
Rifles
Heckler & Koch PSG-1
A Japanese SAT officer aims a Heckler & Koch PSG-1 sniper rifle at Hubert as he exits the bank.
These PSG1 is a Tokyo Marui airsoft gun
SIG SG 540
The Paris police are seen with SIG SG 540 rifles outside the Banque de L'Etoile.
SIG SG 552
There is also a SG 552 in the case
Hand grenades
Mk 2 hand grenade
Momo (Michel Muller) carelessly tosses a Mk 2 hand grenade around after retrieving it from the suitcases he got for Hubert. He later realizes that the pin is out when he "saves" Hubert at the driving range, causing the two to run for cover as their car explodes.
Other
M72 LAW
Momo provides two M72 LAWs for Hubert, telling him they are "heat-seeking rocket launcher[s]... 400 grams each... I got two." Although never seen, Momo also claims to have obtained an "anti-personnel miniature bazooka made in Korea" that "stops a tank at 100 yards", which is pretty much paradoxical, since anti-personnel weapons aren't very suited for anti-materiel purposes...
"compressed air missiles"
Momo also provides "compressed air missiles" for Hubert that can "rip out a tree at 50 yards" for "maximum efficiency".
Deftech "mustard gas launcher"
Momo also carries a Deftech "mustard gas" launcher inside the cases he brings to Hubert.