A lot of the people I ran with got it week one. Some got multiple in that time period. I got two my first and second clears. This is not to brag, but from the beginning, someone had mentioned on here that it was like a 10-15% drop rate based on their calculations - what formula or algorithm they used, however, is beyond me. With that said, I think it's just completely random, as the R in RNG implies. You can have one clear, or 100 it drops when it drops. Ultimately, I now run it to see how fast our team can clear, and if anything else, see what other weapons I can use that aren't "ideal". Just don't think about it, and one day, it'll just pop up like it was meant to be.