Section 8

It is simple really, you have to kill 5 people or bots in a ranked match with grenades or the knife in a row.

Whast this means simple you must not use any other gun or equipment to kill someone besides grenades and the knife.

You can weaken them with the gun then finish them off with grenades or the knife, also you can die they don't have to be in one life that you get all 5 kills with those weapons in a row.

Final Note: you can use only grenades or knives only to get it you don't have to get a single kill with the knife or grenades to get the chieve.

Here is an example of what it mean:
Grenade Kill - Dies - Grenade Kill - Grenade Kill - Grenade Kill- Dies - Grenade Kill

This was achieved really easy, what I did was when a DCM for Intel began for the other team. All i did was spawn a supply station next to me, hid behind it and when the enemy would go up for the intel just throw all your grenades at them. Since you are by the supply you have unlimited so eventually you would get the achievement. :)