James Bond (Sean Connery) carries a Walther PPK in .32 ACP as his personal sidearm. Kerim Bey (Pedro Armendariz), head of MI-6's "Station T" in Turkey, also carries a PPK. Donald "Red" Grant (Robert Shaw) takes Bond's PPK and holds it on him on the Orient Express.
A Soviet guard at the Russian consulate fires a Walther P38 during Bond's attack, but Bond stops him during a small struggle. (Note: Why a Soviet guard would be carrying a Walther P38 is unexplained)
Rosa Klebb (Lotte Lenya) draws a .25 ACP Beretta 418 pistol with ivory grips during her last-ditch attempt to steal the Lektor from Bond's hotel room. Tatiana Romanova (Daniela Bianchi) uses it to kill Klebb and save Bond.
The SPECTRE guards on Blofeld's boat carry MP40s, as do the SPECTRE assassins sent to kill Bond via helicopter or boat. Morzeny (Walter Gotell) leads a boat full of MP40-wielding gunmen.
One of the SPECTRE trainees is reloading a Thompson M1928 as Klebb and Morzeny walk past. Several others can be seen at a rack in front of training station #1.
Bond uses an Armalite AR-7 survival rifle, issued to him by Q, to assassinate Krilencu. Kerim Bey (Pedro Armendariz) eventually does the shooting. Q mistakenly reports the rifle to be .25 caliber, while it actually fires a .22 Long Rifle cartridge.
Note: It is quite possible that Q has modified a normal Armalite AR-7 to accept .25 ACP cartridges