Firefight Commendation system

Games Other Halo
1

This is just a quick question about how commendation points are awarded on firefight. Is it based on individual kills with certain weapons, or is it based on the cR awarded with each individual kill with a certain weapon.

For example:
Killing a single Grunt with the sniper rifle adds +2 cR points to the Dome Inspector Commendation.

2

No, it is based on individual kills. Using your example, a single kill on a grunt with a sniper rifle add only 1 to the Dome Inspector commendation.
The credits that get are added to your actual credit count at the end of the game, helping you rank up.