Actually, my Mag 2000 cuts a 10.25 inch hole with out any effort at all. I do allow the engine to warm up a bit before putting it under load. Also check your oil ratio and if the choke is all the way off. I am strictly concerned with the weight factor because I like to hike into a remote pond and the Lazer hand auger blade is half the weight of the power auger blade.
I suspect if your Mag is having trouble with the 10 inch it will not get much better with an 8 until you determine the real problem. Maybee a simple carb adjustment but it should eat ice easy.