PB, score the log with a circular saw, kerfing it about 1" deep. This will help guide the split more cleanly. Be very careful cutting the kerf so the saw doesn't get away from you. It can be dangerous.
+1 on that. Only way to split elm IMHO. Works good for ash, too. Nice bow Pat B, bye the way!!
Ash isn't too hard to split. Only took me 10 mins to split a 6" log with just a hatchet and wedge.
Elm can be split, its just a lot of work. It can also tolerate some slight grain runout(and is less prone to lifting splinters IMHO), more so than any other wood IMHO. Take a sledge, 2 wedges, and a hatchet, and get to work. Expect it to take more than an hour.
You need to chop the interlocking pieces of grain with the hatchet, after starting the split with it and putting a wedge in it.