If you're at 300 then you should be doing Master if you're not already. it should already be bumming your score up with the event modifier that's been turned on as of todays patch, called Accelerator: Score Multiplier. That plus 2 of the solstice mods (personally like pairing Radiant Joy and Firesprite Fancy), should have your projected score to be a B Increase the score further if need by using the Player Stakes mods. Player Stakes: Equipment Locked Activity is a big score bump. If you still need a higher score then equip No Hud. Remember only the bonus objectives usually need you to kill a specific amount of targets, the score comes mostly from completing the objectives and time saved so dont kill everything if you dont have to. just do the objectives and run through as much as you can without dying. B and B+ are more than enough to progress Hope this helps!