See the thing is the enemies' health differs if they are level 30 they have more health than at level 26 per say. Your armor. If your armor isn't maxed at level 30 you can take more damage than someone who's at level 31 and have maxed their armor out completely. also your class distrubtion and even agility play a factor. If you have higher agility enemies can't hit precision shots on you as easy. Melees grenades, rockets boomers etc can do procession damage. Don't believe me try using the homing grenade with the warlock, hunter. or fire a ghjallarhorn at a cabal or reaver with a big head watch the numbers change on the precision damage. thsi works the same way when enemies kill you especially those hobgoblins and boomers! but the point is. people lie about their experience. its possible to get a group of 6 (5 liers) who say they've ran hard mode before, but never have. All at level 30 with unmaxed gear. I'd rather bring some 31 or 32s in to ensure atleast 3 people if not all 6 of us know what they are doing. When you are on a tight schedule (schoool work etc.)

Melee kills work differently.. I notice a huge difference from being 31 to 32. You have more amour and you can 1 shot goblins in the gut.