In halo 4 all of the primary rifles have different advantages and disadvantages.
I feel BR has slightly more aim assist (don't quote). It needs this because you have to trace aim for the duration of each burst. It is slightly harder to take down someone's shield with the BR even with the greater aim assist. However it is significantly easier to get a head shot on a no shield opponent as only 1 of the 3 bullets in a burst needs to hit, allowing for a h2/h3 style swipe aim easy headshots.
The DMR has an easier time taking down someone's shield with its single shots. You can snap shot style aim, as you don't need to trace if you don't want to. Also at greater ranges every shot it hits will hit for 100% damage, unlike with BR where 1 or 2 of the 3 bullets in each burst can miss. (This is where the DMR gains its range dominance over the BR, not the superior scope IMO) However it is much harder to get the head shot.
I personally think tournament play could allow both, with loadouts, like in matchmaking. But if you have to pick one over the other i think DMR is the best choice. My reason for this is that harder headshots. DMR v DMR allows for people to actually miss the finisher, and because of this a fight is never over till its over. With BR vs BR however, once you are up or down in shots in a heads up, the outcome of the fight is already decided. The finishing shot is easy, arguably even easier that the previous 4 shots for some aim styles.
So why do people push for BR in tournaments, then whinge that DMR is more dominant in matchmaking? Im seriously suspicious a lot of peoples judgements are being clouded by nostalgia. With the huge competitive growth halo had during halo 3, this halo was many peoples first halo, and i feel this is where the BR obsession comes from. As someone who started with halo 1, I have to admit that playing with the DMR in reach gave me a burst of nostalgia. The glorious return of the 'comeback' in heads up fights, that the single-shotting, hard-headshotting DMR allowed, is something halo 1 players can appreciate.
But hey, were all being objective here right? so moving on. What about the light rifle?
The LR has the quickest kill time with a 4 shot kill (4 scoped shots, or the even quicker 1 scoped + 3 no scoped shots), but has the least aim assist. Its burst shots also have a longer duration that the BR, meaning you have to trance aim harder, and be a little less wild on a swipe style headshots. So although it is technically the best primary rifle it is far and away the hardest to use. Not only is there less aim assist, but you have to do a more advanced scoping/unscoping thing with it to get the most out of it.
How is the LR not the far and away the most obvious choice for competitive play? Maybe its just no one has LR nostalgia?
Some food for thought...
The carbine is a little underpowered atm so i wont go into it too much, its harder to use because you need to land more shots in the same amount of time. Pretty simple. However one thing worth mentioning is that once and opponent has no shield, it has an easier time finishing them because its got more 'second chances' with its higher fire rate. The reason i bring this up is because of the proposed BR buff. A slower shooting, 4 shotting BR would in a way be slightly nerfed in regards to ease of head shotting If you do somehow miss the headshot, its going to be longer before you get another crack at it.
