Posted 24 November 2013 - 08:29 AM
One reason I like to use grouped smaller AC instead of single Larger AC is the projectile velocity; it's much easier to hit a moving target with grouped AC/2 instead of AC/5s or 10s because smaller autocannons have faster bullet travel speeds. Likewise, it's easier to hit your mark with dual AC/5 instead of an AC/10. Secondly, dual AC/5 does have a 40% higher firepower output than an AC/10 because of the higher RoF (1.5 sec vs. 2.5 sec). Also, the AC/5 has a much longer effective range than an AC/10, AND is 33% cooler to shoot continuously (2xAC/5 generates 2 heat/10 dmg, but AC/10 generates 3 heat/10 dmg).
So, dual AC/5 weighs 16 tons over 12 tons for an AC/10 (33% more), but has 40% more firepower, a faster bullet velocity,a longer effective range, and is cooler while ammo consumption remains exactly the same (because all autocannons carry 150dmg worth of ammo per ton).
That's the case for why you should take dual AC/5 over a single AC/10.
Now, for the AC/2 story... that's a little trickier. AC/2 is the hottest autocannon by a wide margin (5 heat/10 damage for illustrative purposes), but it has the longest range of the ACs and longer range than Gauss; it has the fast bullet speed of the ballistics (tied with Gauss at 2000m/s, which is MUCH faster than AC/5); it has a high damage output rate of 4 dps (which is equal to a single AC/10, which weighs twice as much), and also it's the lightest autocannon weapon @ 6 tons each.
Grouped AC/2 makes a very fine long-range weapon IF you can keep yourself on target for a while because you practically can't miss Assault or Heavy Mechs out to long ranges because of the very high bullet velocity, the damage output is high, and the range is very long so there's little damage drop-off (even at 1000m, the AC/2 is still dealing higher than 75% of muzzle damage). For a different comparison, dual AC/2 has twice the damage output of a single AC/10 for the same weight, so that's impressive.
However, grouped AC/2 does cause damage spread (you'll be plinking for 4, or 6, damage per volley instead of 10/volley), which is not really a concern when comparing dual AC/5 vs an AC/10 becaus ethey both deal 10dmg/volley. Also, grouped AC/2 is very hot, so if you don't carry extra heatsinks then the 10 Engine DHS will only let you shoot for a little while before you have to cool down or reduce your fire to just a single AC/2 when you get too hot to fire more than 1 continuously. Still, though, it's cooler than any Laser or PPC.
I like using triple AC/2 for long-range support because it deals copious amounts of damage compared to a single Gauss rifle, with the same 2000 m/s projectile velocity, and can be used for some kinds of brawling, too, since it's cooler than lasers and PPCs. You just need to consider the high heat and the damage spread drawbacks, and see how you can deal with them.