In CS: GO added the legendary MP5 Developers Counter-Strike: Global Offensive in his blog told that the game finally appeared legendary submachine gun MP5. True, a little modified. This is the version of the MP5-SD with tightly screwed muffler. The effect from it is really noticeable – gunfire is not audible at a distance of several meters. Weapons are only in games with bots, as well as in the Casual and Deathmatch sections. Apparently, the developers are conducting a kind of testing, as they ask players to share their opinion about MP5-SD.
This submachine gun without a muffler was in the beta version of CS: GO, but later it was decided to replace it with MP7. The usual version was also present in CS 1.6 and CS: Source.