My senior rater screwed me

I'm just did my first ncoer. I'm on deployment as well. My senior rater gave me a 6 and told me I was qualified on the eval. I was the ncoic for him and even did most of the paperwork he was supposed to be doing for him. Im just confused and angry.

I know this is my first ncoer but yeah any tips on getting a better grade from the senior rater without having to get on my knees?