Hi Vazze,
The answer was given in the previous message. There is a custom shop in our server with items that you can buy such as double damage, HP, unlimited ammo etc... to make the game a bit spicier and funnier compared to conventional, more regular servers. Throwing many nades in a row is an item from shop. To buy it, write "/shop" in chat, and then navigate the menu with 9 and then 6.
This is again something that is unknown to new players, who sometimes think that people are cheating while they are not. This is related to reply I wrote a few minutes ago concerning the fact that commands should be documented for new players.
Have a nice day,
Stach