Duke Togo aka Golgo 13 uses a suppressed M1911-type pistol during one of his missions.
Unknown M1911 variant
Used by a female detective.
Colt Python
Duke only used the Python in one of his missions.
Smith & Wesson M36
Used by Golgo 13 as his main sidearm. In the show, it seems to be either a 2 inch 15 or a 14 judging by the adjustable rear sight.
Assault Rifles
M16A1
Used by AX-3 during a joint mission before he tried to turn his weapon against Golgo 13.
M16A2
Used by Golgo 13 as his preferred weapon for sniper work, fitted with a telescopic scope. It is the prominent weapon in the series.
FN FAL
A mercenary is armed with the FN FAL against Golgo 13 in the desert.
AK-47
Encountered by Duke during one of his missions.
Heckler & Koch G36K
A mercenary is armed with a G36K against Golgo 13 in the desert.
Steyr AUG
Inside a rifle case, it contains disassembled parts for a Steyr AUG assault rifle.
FN F2000
Used as the main assault rifle of the younger Savine sibling, an ex-French Foreign Legion soldier turned mercenary after the brothers were paid to kill Golgo 13. It was also portrayed during a rifle demonstration.
Heckler & Koch XM29 OICW
Used by the older Savine brother, who also served in the French Foreign Legion with his younger brother prior to being a mercenary.
Sniper Rifles
Anschütz Target Rifle
Used by Golgo 13 to snipe Jake Quade after took an entire passenger jet full of hostages. The rifle is chambered in .22 LR in addition to seemingly having a different rifle buttstock.
Remington 700
Used by police SWAT snipers against Jake Quade.
Others
AT4
Duke uses an AT4 against Garimpeiro's men, destroying their truck. He bought it when he disguised as a Brazilian military official.
FIM-92 Stinger
Duke uses two Stinger MANPADs in Brazil against corrupt Military police officers, shooting down their choppers after purchasing them under the guise of a Brazilian military official.