Target help

[Djl1977]

First timer here!!!! Big question I am an avid shooter I reload my self an I am experiencing some issues at the range. I shoot a 300 rum sendero 26" barrel and can group really well out to 600 yards and have real trouble at 820. So my question is my 820 yard target is on the face of a hill but about 100 yards closer is the crest of another hill that I am just clearing to shoot at the target meaning I am shooting over a little ravine before impact. So my question is being that I am shooting close to the crest of the closer hill will that effect my trajectory??? No matter what ballistic calculator I use I am right there with my figures!!!! But for the life of me I can not ding the steel and I am confident in my ability and equipment sooooooo looking for some help. Thanks.