User blog comment:VLKAFENRYKA/Space Wolves vs Tyranids/@comment-3258762-20130218202956

Depends.

The Wolves will win against the Tyranids if they face a minor Hive Fleet or, if it takes place on Fenris, a full Hive Fleet, possibly one and a half. After that it's just impossible to stem the tide.

If not on Fenris well, there's not much the 13 companies can do against a Hive Fleet other than blow it to smithereens

I'll actually go with the Space Wolves on this, because it is not sure how many of the nids we face and it seems to be that a normal Marine is the equivalent to a Warrior Beast in one-on-one (based on fluff) but if you say that it's 10 Hive fleets then the Nids win.