Quickswitching is a common method that prevents unwanted automatic re-scoping after shooting a sniper rifle.
This method also literally "increases" the rate of fire for certain snipers, as it skips the bolt action.(Not all)
Although this is so, sniper rifles with slower scopes should NOT quickswitch. This is because slower scopes, when automatically re-scoped scope in 2.5x faster.
There are 2 main ways to quickswitch:
QQ Method-This is easiest to execute, however, newer players may find this method somewhat diffifcult. Basically, the player must press the letter Q on the keyboard twice in rapid sucession.
3-1 Method- This is a much faster quickswitch if timed and executed properly, however this method has drawbacks, such as lower mobility since the player shifts his fingers upwards in order to press the number, however this can be countered of the player adjusts accordingly. This is the most difficult to get used to.
Mouse Roll- The player rolls upwards or downwards on his mouse. Harder to control and slightly slower but very easy to execute and gives good mobility.