Via [url=http://blog.counter-strike.net/index.php/2016/08/15308/]the CS:GO blog[/url]:

[quote=Valve][GAMEPLAY]
– New accuracy recovery method and new recovery rates for the M4A1-S, M4A4, and AK-47. See details [url=http://blog.counter-strike.net/index.php/second-shot/]HERE[/url].
[SOUND]
– Increased fidelity of firing sounds for P250, Five-Seven, Tec-9, CZ75-Auto, and Dual Berettas.
– Added unique reload and distant sounds for P250, Five-Seven, Tec-9, and Dual Berettas.
[MISC]
– Added defusekit player state to game state integration support.
– cl_weapon_debug_print_accuracy 2 is now a tab delimited formatted output of information.
– Fix a bug that rarely caused a player to be on the wrong team in competitive mode.
– Fix a bug that allowed players to spawn in unexpected (invalid) locations on various maps.
– Added logic to prevent airstalling (where a player appears to float in midair by disrupting their network stream).
– Added sv_clamp_unsafe_velocities convar (default: 1) that community servers can disable to support surfing, etc.
– Misc security improvements.
– Modified report and commend GC logic to clearly signal failure in the case of spoofed reports.[/quote]

Rumor has it:

- Wondering about SlothSquadron's analysis? It'll be delayed a slight bit [url=https://www.reddit.com/r/GlobalOffensive/comments/4w1da3/counterstrike_global_offensive_update_for_8316/d6361d1]as he's currently on a vacation[/url]

- You may notice while testing the Dual Berettas that one gun is doing all of the firing, and [url=https://www.reddit.com/r/GlobalOffensive/comments/4w1da3/counterstrike_global_offensive_update_for_8316/d636dmi]IluvYOU69 of reddit says that it happens when sv_infinite_ammo is enabled[/url]. This bug (if you can call it that) appears to be quite ancient, but it's listed here so you're aware if you're looking to test it with a test/practice configuration that includes the infinite ammo command

- [url=https://github.com/SteamDatabase/GameTracking/commit/a14d60023eebf63bc007519117cf6e9419a32628]VPK contents diff, and script changes for the new sounds[/url]. Scroll down for those things, or [url=https://github.com/SteamDatabase/GameTracking/commit/a14d60023eebf63bc007519117cf6e9419a32628#diff-3684e2d69173970d8c50e6c9927cff66L43453]click here to skip most of the irrelevant stuff[/url] as there's a lot of low level changes as well

- Item schema update which adds a bit of white space, as well as a TF2 item schema update thrown in as well because SteamTracking: https://github.com/SteamDatabase/SteamTracking/commit/4418a3fd51256aec144687205ed87c01f7e14f2c

- If you're intending on reporting issues (don't be afraid, you never know if you're not the only one!), and you happen to be on Windows 10, please make mention of whether or not you're on Redstone 1/the "Anniversary Update" as not all issues may be caused by this update itself but by Redstone 1
- Unsure of whether or not you're on Redstone 1? Search for "winver", and if "OS Version" is 1607, you're on Redstone 1. Otherwise, if it says 1511, you're still on Threshold 2

- Size is ~30 MB