Well, I’m going to share with you how to make a FREE nutcracker that WILL crack macnuts, as well as other nuts, and it should take you about 10 minutes [or less]! And, you only need a rock and chisel to make it!
First, find a decently heavy rock, ideally with one flat side. The flat side will rest on the ground so that it’s stable.
Second, use the chisel to create a small rounded hole; you might want to make it about ½” deep at first, then test it to see if it will crack a few nuts and to see if you need to make it bigger. It’s better to make it not deep enough, then test it, then you can make it deeper if need be. And, that’s it! You’ve got a free nutcracker! The only thing you might need to purchase is some kind of hammer. A regular hammer might not work; a 2 or 3 lb steel sledge hammer seems to be ideal for cracking macnuts, but not smashing the nut meat inside the shell. I was able to find a used sledge hammer for a buck at a garage sale! (thanks to G.P. for the idea of using a rock to make a nutcracker!)
The picture below shows a rock with a small hole carved into the middle of it; might be a bit difficult to see, but there is an indentation in the middle of the rock and it works great in cracking macnuts, as it does in cracking other types of nuts, too!