A shael will certainly help you. Bonesnap is WSM 10, with no other IAS, so adding a Shael will bring you down to -10 (lower is better) and the WW breakpoints for 2-handed weapons are 0, -10, -30 and -60. That is 2 BPs higher, you will hit a lot more frequently.
Note though, being currently on the path to an IK WW barb myself, Bonesnap is not as good as Steeldriver for the middle part of the game, if you can get one of those. Steeldriver is speed -20 all by itself, and you can Shael or IAS jewel it to hit -30.
I also recommend doing the normal-exceptional unique upgrade on whichever you use when you get a bit higher (just remember the str and level reqs will go up).
IK Maul is a long way off (I'm not there yet with my guy).