Chances of getting Weapons in Gun Dungeons

In the gun dungeons you can get max. 1 uncommon item (from Easy or Medium runs) and Max. 1 rare item (from Hard or Nightmare runs)

The chances of getting the item are as follows:

Completed runs Chance of success Chance of Failure
1 run ~70% ~30%
2 runs ~92% ~8%
3 runs ~97% ~3%
4 runs ~99% ~1%
5 runs > 99% < 1%
6 runs > 99% < 1%