Ah yes, the Type 64, a Chinese submachine gun with integrated suppressor designed in the 60s for Recons, it was largely equipped and used by the People's Liberation Army during the war against Vietnam, and was ultimately succeeded by the suppressed variant of Type 85.

Gmod version:
https://steamcommunity.com/sharedfiles/filedetails/?id=2754557465

The model was ported from a L4D2 mod with permission granted:
https://steamcommunity.com/sharedfiles/filedetails/?id=2744654539

Includes:
l4d2_mod\zzzs570\type_64\l4d2_mod_type_64.mdl
l4d2_mod\zzzs570\type_64\l4d2_mod_type_64_magazine.md

Credits :
zzzs570 - Original creator of the model and the L4D2 mod.
NeoLin - Porting to Gmod and SFM.

Feel free to support the Lambda Group for more addons.??
https://ko-fi.com/neolin7812
https://www.paypal.com/paypalme/NeoLin7812