I have a LK-II 93 and it shoots great with 90 grains of Goex 3f and the 240 grain T/C Mag Express XTP's.
I never shot off a lead sled. If this is something new you just added, as suggested, try a different rest. It sounds like you're doing everything right for accuracy. So somewhere there has to be a glich. Check the scope mounts, the bases, etc. Those Wolverines are normally a great shooting rifle... Sorry to hear of your troubles.