My iron tested 276 out of 50-160 ref range, I have been taking a supplement called "blood builder' which contains iron. How dangerous is this level?

Too high....hemochro. Your iron level is much more than what is needed and thus not a good thing...there is such a thing as too much. As a male, you do NOT have a natural way of losing iron (females menstruates monthly), excess iron build up can cause liver,pancreas, heart trouble, even testicular failure---hemochromatosis = excess iron. So pumping iron and testicular failure maybe opposite of want you want...