It's 130% attack speed on shit-tier base AS at 525 range. Any ADC with an AS steroid out-attack speeds her during their buffed time, and in Tristana's case, does it from Fishbones range. 525 range is DANGEROUS. You are in range for everything. You aren't doing max-dps on Jinx 90% of the time in a teamfight because that places you within range of anything that wants to hit you.
She doesn't have 130% attack speed in rocket mode. People don't seem to understand that if they haven't played her. She has it on the first attack after switching, which is why finishing some one off with that last Fishbones shot is useful.
Using her rocket mode before you get attack speed items to make up for her shit base AS(because the rocket isn't getting the 130% minigun's attack speed, remember) is miserable. Try it. You'll cancel the auto half the time because it shoots so fucking slow.