The NHS gets an obscene amount of money thrown at it as it Is, needs to sort out it's procurement and admin wastage.
Extra money for the NHS wasn't a factor in me voting leave as the organisation squanders more than enough already. But you want your extra 300 mill a week ask the government why they squander 13 bill on foreign aid to countries such as nuclear armed Pakistan and India. There is your 300 mill a week give or take a few quid here and there.