I Regret Nothing Achievement in Halo: The Master Chief Collection

I can only get 17min. What am I missing ?

The level is so random heavy, it is very challenging. Just check Naked Eli on youtube, he has a 11ish minute legendary run. Its very random heavy.

The only way to do this is by using the Sputnik skull. After you get out of the starting building there is a broken bridge to the right, grenade jump across and then from there work your way to the left and grenade jump again to the gondola that takes you across the water. immediately walk off the gondola and onto the platform, the gondola will start to move across. jump back on. From here it's business as usual and overall it should save you 2 minutes

VIDEO GUIDE http://youtu.be/RPfo_x4_csQ

I was able to do it without sputnik with about 30 seconds left or less, all I did other than speed through and kill only the essentials (basically the other gondolas, the hunters, jackals, and elites before the first gondola, and the first elevator room)was that I used a grenade to jump over to the bridge that goes to the first gondola area (not the broken bridge, go as you normally would but before entering that first building turn right, throw a grenade in the little tower/bowl thing and use that to skip the building).