So you know how Master Chief's armor changes from Halo 3 to Halo 4? Why and how?
In Halo 3 he has the Spartan II version with the chestplate damage. In Halo 4 he has the Spartan IV version but he still has the damage. This would mean its the same armor even though it is a completely different version. However, he couldn't have changed armor because he had been unconscious on the Forward Unto Dawn for 4 years 7 months and 10 days.