Improving an ax for this purpose is quite simple. A scallop is welded to the ax. After that, an expansion wedge is driven into the ax and the butt with it is drilled through. For reliability, the connection can be fixed using a thick nail with riveted ends, which is threaded through the wedge and ax cheeks.
Second Ax Option, to which a “comb” of a different shape is welded, can be used as a wedge. "Scallop" reliably protects the butt from cracking when struck with a hammer from above.
