I'm getting some conflicting reports. Is Stormbreaker just a Mjolnir clone? Just reading up on the web and it says that S.B. has the same qualities s Mjolnir. I could swear S.B. has different effects, almost like "cosmic/magnetic" type stuff....
Also is B.R.B. class 100 without his Hammer? Is he Thor's physical equal without the hammer?
It was made by the same dwarves that made Mjolnir and given the exact same enchantments by Odin that he gave to Thor's hammer. It's supposed to basically be identical to Mjolnir except for its appearance. There was a period where Bill didn't have "Thor" powers and his hammer was different, but the hammer and Bill were later restored to their original states off-panel.