Silent Storm - Mjolnir Dura

Sparks began to flash along the grav tube walls. A projectile deflected off John’s shoulder armor, and he checked his motion tracker. Five hostiles were clinging to the wall twenty meters behind him—which meant above him, since he was descending the grav tube face-first. He rolled onto his back, then felt more impacts as two more projectiles burrowed into his titanium breastplate.

Still wasn’t a disaster, but getting closer.

A line of the saurian aliens was hanging above the closed hatch, each clinging to a built-in utility ladder with one hand and firing some sort of Covenant carbine…

…John ejected his ammo clip and reached for another, enemy rounds still impacting his armor, mostly glancing off, but some burying themselves deep in the titanium shell.

A little deeper, and it would be a disaster.

- Halo: Silent Storm, Chapter 3