This is a longish post, so only read the first paragraph if you don't care about the details.

With an upcoming update, the speeds of the various weapons will be adjusted to match the rate of old 100 tick servers.

There was a long-standing bug in CS with how the weapon firing rate was calculated. Imagine that the AK fired 6 bullets a second (166ms), and the server updated at 10 frames a second.

Server update 0: 0 ms Firing timer: 0 ms
Server update 1: 100 ms Firing timer: 100 ms
Server update 2: 200 ms Firing timer: 200 ms => *FIRE* => 0 ms
Server update 3: 300 ms Firing timer: 100 ms
Server update 4: 400 ms Firing timer: 200 ms => *FIRE* => 0 ms
Server update 5: 500 ms Firing timer: 100 ms
Server update 6: 600 ms Firing timer: 200 ms => *FIRE* => 0 ms
Server update 7: 700 ms Firing timer: 100 ms
Server update 8: 800 ms Firing timer: 200 ms => *FIRE* => 0 ms
Server update 9: 900 ms Firing timer: 100 ms

As you can see, 33ms of firing time is lost each time the gun fires- it's effectively shooting slower (only 5 hits / second) because of the tick rate of the server. If the server was bogged down or had lot of people on it, the results would be even more unpredictable.

This is why guns operated very differently at different tick rates.

We've updated it to the correct behavior, in which case you'll get:
Server update 0: 0 ms Firing timer: 0 ms
Server update 1: 100 ms Firing timer: 100 ms
Server update 2: 200 ms Firing timer: 200 ms *FIRE* => 33 ms
Server update 3: 300 ms Firing timer: 133 ms
Server update 4: 400 ms Firing timer: 233 ms *FIRE* => 66 ms
Server update 5: 500 ms Firing timer: 166 ms *FIRE* => 0 ms
Server update 6: 600 ms Firing timer: 100 ms
Server update 7: 700 ms Firing timer: 200 ms *FIRE* => 33 ms
Server update 8: 800 ms Firing timer: 133 ms
Server update 9: 900 ms Firing timer: 233 ms *FIRE* => 66ms

This fixes the integration, and regardless of tick rate, the guns will have the same feel. In practice, this made the difference between 8 (33 tick), 9 (66 tick), and 10 (100 tick) bullets per second on the AK. Now they should all be identical.

In order to preserve game play, we timed the guns and dumped out the delta between shots on the old 100 tick servers and the new servers. Every automatic weapon was tested, and then we modified the weapon data to match the old 100 tick results.

After making the changes, we ran through and verified that the firing rate was the same for all automatic guns as it was on 100 tick server before the update.

The final cycle times (in seconds) are given below:

SMGs
MAC-10: 0.075
MP5: 0.08
KM UMP45: 0.105
TMP: 0.07
C90: 0.07

Rifles
AK47: 0.1
Galil: 0.09
552: 0.09
D3/AU-1: 0.25
Scout: 1.25
AWP: 1.455
550: 0.25
Bullpup: 0.09
M4A1: 0.09
Famas: 0.09

Shotguns
M3: 0.88
XM1014: 0.25

Machineguns
M249: 0.08

With this update, all of them should feel like old 100 tick servers.

We also plan on looking at weapon recoil and spread patterns and fixing the integration problems there, as well, but that will be in a later update.

Thanks!