RE: Magnus Stinger
Stingers are great heads and are very durable and extremely sharp.
However the 85 grain head may not be the correct weight head for you to shoot and get the best possible flight from your arrow. Depending on your archery set up you may be better off with the 100 or 125 grain stingers.
I can almost guarantee you (about 90% certain) that you would be better off with a heavier broadhead than the 85 grain.
Don't just go buy the 85 grain head just cause your friend says they are good.