>>>I tried my ground beef tonight - it turned out pretty soft. It was fine for pasta sauce and will be good for tacos. But not for anything that needs it firm. So, a tougher cut of meat would probably turn out nice and tender.<<<
Yep, that is why I use flank steak, and other tougher cuts and run them through the old #10 grinder with a 3/8” plate for ground beef in canning (3/8” makes it great for chili), or cut them into cubes. The finer grinds seem to lose more body when canned - I save that for sausages, where you want it a bit finer (actually double grind for summer sausage, lebanon balogna, etc.)