The pricy G3SG1 lowers movement speed considerably but compensates with a higher rate of fire than other sniper rifles.
Damage chart
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Although it has a high damage output, there's a reason the G3 is one of the least popular weapons in the game, it is not a very good offensive weapon! Which makes the Terrorist side more difficult, and if you die, you absolutely wouldn't want this gun in the hands of the CT players.
See it in action!