That's not how maths work. You're describing something that works for non-dependent events. Flipping a coin 50 times previously has no bearing on how it will flip the 51st time. The events are said to be independent.

In a six round revolver loaded with a single bullet and then randomized, pulling the trigger advances the next round. The first pull has a 1/6 (or 1/600, whatever) chance of firing. You will fire (assuming no mechanical malfunction and no randomization of the round after each pull) in those first 6 shots with a probability of 1.