Agree Sambucus melanocarpa (better treated as a species: Eriksson & Donoghue, Systematic Botany 22: 555-573).
Sambucus racemosa var. melanocarpa is also the name used by both the upcoming edition of Flora of the Pacific Northwest and the Jepson eFlora, so that's what I'd go with. The authors of both of these works would have reviewed the Eriksson paper.