Hi Goffick
I used two mauls, hand held, one about 16oz and one about 10lbs. The big one worked like a sledgehammer and the small one like a carpenters hammer. I made sort of a leather sling for each, with the striking surface exposed through an hole in the leather, I was amazed at the kinetic energy that could be produced. Even though I am unskilled with such a tool the accuracy was reasonable, with a few years practise I reckon you could hit a sixpence with either.
I have a book coming out in Sept BTW, will have the details on my website shortly including a sample read, pictures of the North Ferriby boats and details of my experiments in America.
Always good to hear from any of the Stonehengineers
Gordon