In all honesty, 20 maybe on the high side. I know of and have shot a 18 pounder, and the owner of which I speak to regularly in the boozer says it still does kick somewhat, it's nearly 20 years old. However, it's wasn't that bad, if you've shot a 25 foot pound Eliminator, it was nothing compared to them rammers.
If I had my ticket, a heavy duty life taking FAC HW80 would be on my f'kin list. Nuff said.