Maybe it's time to start thinking about using a wedge and a sledge...

[Dune]

The well-tested repair I mentioned above was a new Sch.40 pipe handle welded to old stub, with a 4" sleeve welded over that.

The thing is you just moved the weak spot to the end of the pipe sleeve. We use steel handles on sledge hammers on commercial boats. Good for x number of hits until metal fatigue sets in. The only thing that ever worked was to weld in a solid plug about 18" long, then pipe over that, with about 4 plug welds. Moved the weak spot far enough away from the head that the leverage length of the handle was no longer an issue. In the case of a monster maul, the weight of a long plug becomes an issue, since the stupid things are already too heavy. Hence it becomes a maintenance issue. Repair as needed. Without doubt though, a sharper maul will not stress the handle as much.

 

[Osagebndr]

Get a 8# maul and get away from the MM. IMO it's great on some stuff and not really great on anything at all , especially the back. I have a grans fors bruks maul and my bil has a fiskars splitting axe, both work great. If it won't split on one side flip it and try the other or get some wedges. Large rounds need to be worked from outside in . Slab them down and resolution the slabs if need be and if all else fails noodle it down