Instead of running the full dungeon every time, you can just save the final boss checkpoint and farm it. With a fireteam, it's a fairly quick encounter.

[quote]I completed the grasp of rice today 3 times solo and fireteam but still no new rewards like the helmet or the sword am i doing something wrong ??(i don't play on difficulty)[/quote] The rewards in Grasp of Rice are RNG. You aren’t guaranteed items you don’t have so you just need to keep farming until you get what you’re looking for.