One of the Latin American military soldiers flashes a M1911A1 when he takes Bond into custody.
Walther PPK
A Walther is seen only once, being held by a gloved hand infront of the woman during the title secuence. It is never featured during the film itself though.
Walther P5
James Bond (Roger Moore) carries a Walther P5 as his sidearm in this movie, despite having told Q that he "mislaid my PPK". This was to appease Walther, who wanted to promote a new pistol. Interesting to note is that this was the same pistol used by Sean Connery's version of Bond in Never Say Never Again, released the same year.
Makarov PM
The woman in the title sequence are seen holding a Makarov PM.
One of the U.S. Air Force Security police guards manning the gate at the West German U.S.Air Force base carries a Colt Python, which he draws on Bond when he attempts to enter with the German Police hot on his tail after stealing the car he is in. Because of the many civilians milling around, the guard is forced to fire his six shots into the air, to alert his comrades to the security threat.
Smith & Wesson Model 36
Octopussy (Maud Adams) takes a Smith & Wesson Model 36 from one of the Air Force officers at the circus and uses it to blow the lock off the base of the circus cannon, revealing the atomic bomb inside.
Astra Cub
During the attack on Kamal Khan's palace, Octopussy (Maud Adams) pulls a nickel plated Astra Cub on him, but is knocked out of her hand by Gobinda (Kabir Bedi). An Astra is also held by a woman in the title sequence.
Rifles
Fake M16 Rifle
During the precredits sequence in the unknown Latin American country, the soldiers all wield Japanese MGC M16 replica rifles with 20 round magazines. The soldiers guarding James Bond (Roger Moore) after his capture are armed with M16s, after Bond pulls their parachute ripcords, commandeers one and uses it to shoot out the truck's left front tire, causing it to crash (it then becomes a blank-firing M16 for that part).
SKS rifle
Several Soviet soldiers and some of Kamal Khan's guards can be seen with SKS rifles.
AKM/AKMS
AKM and AKMS rifles are used by virtually all of the Soviet Soldiers in the movie.
Oddly, carbine versions of the Steyr AUGs are used by a few Soviet soldiers in the movie. This is likely the earliest appearance of the Steyr AUG in a Hollywood film.
AK-47
The East German border guards use milled-receiver AK-47s.
SA Vz. 58
The SA Vz.58 is used by some of Kamal's men, and Bond (most notably while sliding down the banister).