I think before any changes be made, we need to lower the autoaim and aim assist levels to that of Halo 3.
Then, we can look at the weapons.
The DMR should have the least amount of autoaim for all of the starters. It should be difficult to use and only able to barely kill two people at range without reloading.
The BR should have way less aim assist too. Other than that, I think it is fine being a 5 shot kill. If it becomes 4sk, then you need to slow down the rate of fire so it doesn’t kill so fast. And by doing that, now it has the ability to kill 3 people without reloading. 4sk is not an option. It needs to stay at 13 bullets.
The Carbine should have closer to 30 rounds, fire much faster, but do less damage per shot. It shouldn’t have high aim assist levels either (nor range) but it should kill the fastest from close-mid range when being used by a skilled player. The point is for this gun to be more difficult to use than the BR because of needing to land more shots but it should balance out with having less range but faster kill times.
The Light Rifle should become hitscan just like the rest of the weapons and have a hip fire killtime slightly higher than the BR (but less than the DMR).
The AR can more or less stay the same. Just so long as it is balanced with the new precision rifles, it should kill unshielded opponenty quickly and should be able to burst fire effectively at mid range like it does now.
The storm rifle should be completely different than it is right now. Right now, it is just an AR with less range but the ability to shoot more without reloading. I think it should actually be a long range AR. It neither excels at killing people up close nor at range. However, it would have a scope much like the ODST SMG and would be able to knock people’s shields out at mid range faster than any other primary weapon.
Think of the hammerburst from Gears of War 1 with the scope feature. Unscoped, it is about the same as it is now: not that great.
It should have bloom so that a full burst of the trigger can knock out an enemy’s shields but the bloom should take a while to reset so that the powerful damage done to the shields doesn’t continue and kill the enemy extrememly fast. This would make an amazing support weapon and would excel with the use of teamwork.
The Suppressor should also change from being the short range AR that it is now. It’s damage at close range should stay the same but energy bolts would change from yellow to a purple color past 30 feet. So right at the middle between short and mid range, the properties of the projectiles should change. Even though they do less damage since they are all inaccurate and weak, they should now slow down the enemy’s speed by 25% and completely prevent sprint for 2 seconds after being hit with each bolt.
Again, this would give the weapon some power up close like it has now but also make it useful as support at mid range.
Halo needs creative weapons again. The first step is giving the less “utilitarian” weapons two functions. Automatics should only be viable up close but should also be useful at mid range as well in order to help teammates.