The max is 7 hammers and that's if you don't have to take a break from throwing to find another target. It's not unlimited bro come on. Getting a kill with all 7 hammer throws is more rare than a full team wipe from a Golden Gun. Not saying it has never happened. But it's definitely not a common occurance. I'd say average is 3-5. Less on larger maps where hammers are easy to dodge.