Agreed, and you may want to wait for them to get closer before opening up anyhow for maximum damage. On the other hand, if a squad of dudes mag dumps an enemy group at max range, they may be able to score a few kills and still have room to maneuver without fear of being instantly assaulted. Further, it could cause enemies who would otherwise be assaulting you, or an objective, to fall back or take cover. While it won't be super effective to engage someone at that range generally, it could have some strategic uses and should be in the game.
That is what I anticipated, which is why I propose that every weapon should have the same factors (projectile speed, damage fall off and effective range) affecting its effectiveness so that everyone will have to deal with the same mechanics instead of just part of the population that is using non-hit scan weapon. Dev can do what most of the shooters out there do too, that is boosting non hit scan weapon to be more effective compared to hit scan weapon when they are in range. Non hits scan weapon usually lose most of its effectiveness at longer range due to players able to see the projectiles traveling through the air, making them extremely easy to dodge. Still I prefer that everyone having to deal with the same mechanics but in different degree like a standard bolter will have standard projectile velocity, lower spread and higher effective range with lower damage fall off compared to a twin-linked bolter that has a higher rate of fire but wider spead, lower effective range and higher damage fall off. A lascannon shot will simply dissipate into nothing when it is outside of the max effective range. But there must be a reasonable range limit as well, you don't want to get shot dead by a lascannon the second you exit the base by someone that you can't even see because he is doing it from few kilometers away. That just make everyone required to pack 1 extreme range weapon at all time. Never played Halo, but I do know how Quake 2 and 3's rail gun and UT's shock rifle and those are extremely powerful especially the rail gun.
