There seems to be some confusion in this thread about how LRM's actually work at present. Here's some details I've learned from using them:
-LRMs generally target the upper portion of a mech, with a very large amount of spread. Expect to primary hit the side and CT, followed by the arms, followed by the ground. Yes, a lot of missiles go straight into the ground. Somewhere around 20% vs a stationary target, and going up very very quickly vs a moving target. That's what improved missile tracking from Artemis and TAG are for. They are most definately NOT doing full damage at max range.
-Each missile is treated individually, not in groups of 5 like the TT and MW4 did. They tend to spread out from center shotgun-blast style, with most missiles hitting the center of target.
-TAG and NARC not only maintain a target lock, they improve missile accuracy. This means fewer of them end up in the ground. That's all.
-NARC gets blown off the target mech as soon as any missiles hit it. This means 1 NARC = 1 missile volley hits with 15% more of it's missiles. For this underwhelming ability, you give up 3 tons of launcher, a missile hardpoint, and 1 ton of ammo per 6 shots. NARC is {Scrap}.
-Artemis reduces lock time and increases missile tracking. The first buff is always active, the second buff requires you to have line-of-sight and doesn't work on indirect fire. Missile accuracy goes up to (a rough estimate) 'only' 5-10% of missiles hitting the ground vs a stationary target. Assuming you have LOS.
-LRMs take almost 10 seconds to hit a target 1000m away (guessing at time, not logged in to go test). This is a very, very long time and guaruntees you won't hit the target unless said target is stupid.
All of this is where my suggestions in post #2 came from. Indirect fire gets a tracking penalty; this is a substantial damage debuff. Artemis extends missile flight range; with the line-of-sight limitation, it's just not that useful atm. Increased missile speed means that it's possible to actually hit at max range- this is balanced by the requirement to hold lock, which means you are either dependent on your team or exposed to return fire.
In their present form, I occasionally use LRMs on medium range flanking builds. An Artemis equipped LRM 20 is deadly on open terrain at 2-500 meters, when supported by other weapons anyway. Using them as long range fire support or indirect fire support is simply not practical. Also, ECM leaves them dead in the water, which is another thread. Literally. There is another thread about it right now. So I won't bother discussing it here.
Edited by RandomLurker, 28 September 2013 - 10:22 AM.