Use the player stakes, no HUD, no starting ammo, brawn. Then you can set enemies at 420-430 to get A reward. Using a hunger that matches your elements in use will act more like a buff than a nerf.

I’m at 405, and discovered a couple of things when struggling with the same thing you are. First, using all “approved” gear is really important. I found having just one weapon be non-approved lowered my expected score by about 30,000 points. Also, the banes add more to your challenge multiplier than the modifiers. So you get more of a score boost for the -20 power delta from a bane than from a -20 modifier. I’ve found if I add just one bane, putting me at a -20 power delta, my expected score is 830,000, which makes getting to the 847,000 score required for an A pretty easy with the bonus objective and timer bonuses. That said, some of the solo ops suck more than others. Like Creator today is doable, but nowhere near as easy as Caldera, K1 or Skywatch.

For Fireteam Ops it can at times be difficult to reach A Grades on Grandmaster due to the countervailing forces of the Bonus Timer and Combatant Takedown scoring. Solo Ops on the other hand should be fairly straightforward; a matter of stacking both your Challenge and Reward Multipliers as high as possible and making sure you complete the Optional Objective and finish within the time limit. At 410 Power I’m able to get A Grades in Solo Ops with only a -20 Power Delta (ie. at 430 Combatant Power). If you post a screenshot showing a Solo Ops Customization menu with your usual Modifier selection and your cursor hovering over the right hand edge of the Reward Score Forecast bar (so as to make your Challenge and Reward Multipliers visible without obscuring your selected Modifiers) I could try to offer some advice. (΄◉◞౪◟◉｀)