What are the odds ??

35/1

Unlucky if you were playing Russian roulette....

5 times 4 shirley 20/1

or is it 29/1?

35/1 (agree with Trilby)

It's a double on two 5/1 shots -> 35/1

yes of course, i was counting second chance as 4/1 shot.

5/1

If you rolled a 6 sided die twice there are 36 possible outcomes. 6 of the outcomes are doubles.

Each separate event is 5/1, so if the gun fires the first time, the odds are still 5/1 against it firing the second time.

However, the odds are 35/1 that you that the the two events will occur as per the OP.

The odds are slightly affected by the weight of the bullet rendering it less likely that the bullet holding chamber will stop at the top meaning it’s not quite 5/1 a fatal shot.  A tad longer in practice. Scant consolation if it is though.....

It`s a pointless question as you can`t bet it happening under the "related contingencies" Rule.