Indeed, some very tolerant people can take an extended release 80 mg oxycontin tablet. However, that could be a very dangerous pill
for another person,
for whom it was not prescribed. And if you cut it it becomes even more dangerous (hopefully this is harder with the newer formulation).
Never, ever take an opiate medication meant for someone else. Many opiates on the market are only safe for people who are already "tolerant," and that is a determination to be made by a doctor.