An important point that people make is the shrapnel effect. Yes splitting wedges will mushroom. If you've used chisels, you will see that they will as well. these are designed to do this. The main part of the tool is heat treated for strength, and the end being struck by the other tool, is made to mushroom. If you hit an ax with a sledge hammer you could be in real danger. Both are hardened steel, neither made to mushroom. This type of misuse of tools can have steel shoot off worse than those made to mushroom.
What type of wood are you splitting? Green or seasoned? knotty or not?
Put up some pics of the rounds.
Shorter lengths will be easier, so if you have a lot of trouble due to twists, knots, stump cut rounds, you will be able to split it easier if you cut them shorter. If you are ripping, you will find it easier to cut from one bark side of the round toward the other bark side of the round, as compared to cutting from one flat, crosscut surface toward the other crosscut end. You will be cutting with a standard crosscut chain (unless you buy a milling/ ripping chain).
Not only are the right tools important, your technique as well. Some people have said that all they need is an ax, which someone pointed out is for chopping not splitting. Axes don't have the same taper as a maul, or what Fiskars may call a "splitting ax". You can split green knotless alder wood all day at 20" with an ax, but different woods, you may get nowhere fast at 12", especially knotty wood.
The proper swing is all important. You'll probably be able to find videos that will show clearly what I'll try to explain.
I'm right-handed, but can split both ways, though more comfortable, and accurate with my left hand at the bottom of the maul. Leather gloves allow the slide that accelerates the head of the maul. I basically have my right hand at, or near, the head, near my right shoulder. I lift the head up slightly behind my shoulder and somewhat overhead, not to the point of being straight-armed. I start by pushing my right hand forward, pulling down with my left hand. Right hand keeps pushing forward and down, sliding down the handle, meeting against my left hand upon contact with the round.
Through this motion, I'm bending my knees and dropping my body somewhat to add speed and energy to the maul. Kinetic energy (moving energy) = 1/2 mass x velocity (squared). Increasing the speed slightly magnifies the force because its exponentially squared.
Gloves are a good idea, but nothing compared to eye protection!
Also, having a large splitting block (round of wood) will help a lot. This will reduce the energy absorbed by the ground compressing, and protects the edge of the maul when you make it all the way through.
The edge of the maul is not as sharp as the edge an ax, as they are two different tool with two different purposes.
Post a pic of your equipment, too, including the maul's edge.
You can duct tape a pad around the shaft near the maul's head to protect if from missed blows to a wedge. I believe that if you maul has a flat back side, opposite the wedge side, it is just fine, and designed for, pounding wedges.
Nothing like practice to increase your strength, technique, and accuracy.