Another way to utilize the nuts, rather than pick out the meat, is something I read once and can't remember where, about how the Cherokee utilized hickory nuts. They would just smash them and put him in a kettle of water over a fire, after heating them for a while, they would strain off the smashed shells and meat, and then skim off the oil, which they used to cook with.
I have never tried this, and don't know what temperature and for how long they were cooked. I would imagine the nuts would have been thoroughly smashed with either rocks or a hardwood mortal and pestle to be able to extract as much oil as possible.
As far as just cracking the nuts, I have heard of people driving over them. The native method would have been using one flat rock with an indention (metate) and a smaller hand sized rock to strike them with. Once you get going with the right amount of energy in the swing, it goes pretty quick. Picking the meats is what takes the most time. You can use various methods to concentrate the meat from the shells, but if you don't get all the shell pieces out, you are going to have some unhappy chewers.