"Using a gun is a matter of knowledge for an assassin, not terribly abstruse, easy to learn but hard to master.
In James Bond movies, the PPK is Bond's main handgun, and because spies and assassins operate in highly similar environments, Chen Guangxin also used a PPK.
But Gao Yi had a PPK and didn't use it, he brought a Makarov PM from the safe house.
The Makarov PM is compact and easy to hide. Although it was a Soviet attempt to replicate and improve upon the Walter PPK, and their appearances are highly similar, Gao Yi chose the Makarov over the PPK because the Makarov is easier to disassemble, maintain, and much less prone to malfunction.
Furthermore, the 9x18mm PM ammunition used by the Makarov PM is more readily available and packs a bit more punch. Therefore, nowadays, many in the assassin circle actually prefer the Makarov PM to the PPK.
