Let’s put it on the table…
Carbine does the same DPS as DMR.
DMR has 14 rounds in one mag. You can very easily kill 2 people with one mag.
Same goes for BR, although many people are experiencing the BR being weaker than DMR.
Both BR and light rifle (unzoomed) have the ability to kill someone with a small bit of shield on.
Light rifle does extra damage when zoomed in.
Carbine has 18 rounds in one mag. You can theoretically kill 2 people with it.
Carbine has the least damage per magazine of all loadout precision rifles.
Carbine has the longest reload time of all loadout precision rifles.
Carbine has the lowest aim assist of all loadout precision rifles.
Carbine has the highest “effort requirement” of all loadout precision rifles.
My suggestions:
A - Damage buff (one less shot to take down shields)
B - Slightly larger magazine (20 rounds) + reload time of DMR
C - Larger magazine (23 rounds)
D - Reload time shorter than DMR