How long should you cook a 6 ounce burger for it to be medium rare?

Ground beef should ALWAYS be fully cooked! It's not like eating a steak rare. More people have gotten sick from eating partially cooked hamburger (and there have been more recalls from companies on produced ground beef that is bad) so, take a risk ... eat it rare or hit the ER. It would take about 2 minutes on each side (enough to brown the meat quite well on each side. If in doubt about the inside, then take a fork and partially and gently pull a little of the meat apart in the middle of the burger.

Don't say you weren't warned about eating rare hamburger.

Do not believe the above Propaganda. It is also not the answer to the question. The question was how long one should grill a half a pound if you WANT it rare. 3 minutes on each side should do the trick. Make sure the grill is really hot when you start.

Bon Appetit!!!