Board Thread:Wikia Discussion/@comment-27279544-20170528163214/@comment-26154973-20170613144110

Note that 20% is multiplicative, that is, 2% SSR weapon drop rate becomes 2% * (100% + 20%) = 2.4% (not 22%), with other buffs (crew, journey drops, esseru, weapon, TH) it can be 3-6%. And then you want a specific SSR weapon, so it's then 2-6% / salt.