I am painting up a couple squads of spacewolves and I'm trying to decide on the primer. Should I prime them black and then brush paint shadow gray, or should I spray them white/basecoat shadow gray/ink black/drybrush shadow gray? I also have gray primer if anyone has experience using that.
Thanks in advance for your thoughts.:D

I've never been a fan of priming white.

I'd go with: -> black primer-> shadow grey basecoat leaving black in the crevaces-> 1/2 shadow grey 1/2 space wolf grey highlight -> Space wolf grey 3rd highlight.

Yeah I used the same technique and it worked fine for me in the past...

Also I had used drybrushing all over the model for a more dirty look!

When I did my space wolves a few years ago, I had a horrible time doing black. I went:
White primer --> paint a thinned down shadow grey over the whole model(or, if you can find it, spray it on) --> drybrush or blend up with spacewolves grey, and highlight with space wolves grey up to white.