The best sniper who has the fastest ADS time and firing time increases your chances of winning by 50% the other 50% depends on your skills, cod mobile have many guns which have the fastest ads time but they are the worst because they have the worst reloading and firing time but some have the best reloading and firing time with best ads time.

Fastest ADS sniper in cod mobile

I am going to tell best all-rounder sniper which has best features on every aspect.
svd is one of the best sniper in cod mobile which has the fastest ADS time including the hight firing and reloading time. My second choice is locus gun as it has a 15% higher damage rate than svd, but it has a bit slower ADS time than svd.
The Outlaw has a faster ADS time than that of SVD, but it is the worst gun in my opinion as it has the worst firing time and is not as stable as the SVD gun.
Players around the world use svd rifle while playing competitive matches while some refer locus rifle as it has more damage than svd rifle.

conclusion

SVD has the fastest timing and firing time, it is an all rounder rifle that best fits every aspect, This can be the best sniper for those players who kill the enemy by reaching close to them.