Morbid but, assuming 6 slots in a revolver then the chance is 1/6 per try, or 5/6 chances of not shooting yourself dead.
The probability of “winning” is thus 5/6 per try. Trials are independent, since winning once has no bearance on the next try. A year has 365 days so you would need to win each time, the final probability is thus: (5/6)^(365 * 40) which according to the internet is: 8.5427038e-33
Or in short, you are not winning this game, don;t win stupid prizes, and I really hope this is just a morbid thought experiment and you are not trying to actually go throught with this.