Can you explain or rewrite the formula please did the math and came up with 242ms.
I have edited the post to correct values. I used 390 instead 360 m/sec. My fault. But the difference is 0,024 sec, that is 24 msec (and not 242). The concept is the same.
The formula explained:
TTK = Time to arrive 1st bullet + (n-1). (60 / ROF)
Starting at the time you pull the trigger, the first bullet takes to hit = DISTANCE / bullet speed.
If you need "n" bullets to kill, the following bullets (n-1) leave the gun with a spacing of 60 / ROF sec (ROF are rounds per minute = 60 seconds)).
After the first hit, the second hit will be at 60 / ROF sec later.
And the last hit to produce DAMAGE> 100, will be at (n-1) * (60 / ROF) sec more.
The total time is the one that provides the formula. OK?
Labby point of view is very suitable, because I've done the calculation Naked Weapon vs Suppresed Weapon, but it is usual to use the suppressor INSTEAD of another attachement and this gives a different probabilistic TTK (It could be greater or smaller depending on the distance).