The bullet travels so fast from the time the primer is ignited. powder ignited and bullet leaving the case and traveling to the end of the barrel say a 24". But the other factors are involved with twist rate, groves, bullet so let's just leave that out and make it simple with just velocity of say 3,000fps.
To answer your question, we can use the formula for time, t = d/s, which means time equals distance divided by speed1. In this case, the distance is 24 inches, which is equivalent to 2 feet, and the speed is 3,000 feet per second. Therefore, the time it takes for the bullet to travel 24 inches is:
�=��=23000=0.00067 secondst=sd=30002=0.00067 seconds
This means the bullet travels 24 inches in less than a millisecond!
The most critical part of firing a rifle or any other firearm is the position of the firearm barrel to the target.
If you shake/Jerk the firearm while in the process of the ignition of the cartridge and take the direction of the barrel off course of the target it will most likely miss.
BUT if you can hold the sights on target from when you start your finger on the trigger to ignite the cartridge within a "Millisecond" you should be just fine.