Leg of lamb is not tough generally, I personally would cut that down to no more than 18 hours if it is bone-in and probably like 8-10 hours if boneless, dependi

Leg of lamb is not tough generally, I personally would cut that down to no more than 18 hours if it is bone-in and probably like 8-10 hours if boneless, depending on size. Edit: A few websites suggest something between 5-8 for boneless.