I'm really starting to like the combination of LB-10-X AC and AC2 or UAC2. I've run something very similar on several 'Mechs now, and just tried this one out with some buddies in group queue last night to great effect. The 4xERML gives you burst, but the Autocannons are almost heat neutral and absolutely punishing. Also, the triple range modifier on the 10 lines up well with the already longer range on the 2s, which means your maximum range for both converges nicely, and even at the optimum range for the 2s, your 10 is still punching nicely, albeit with a bit of spread by that point. I was running it with a macro on the ACs to space the fire more evenly, but regular chain fire might work just as well, since the ACs have no duration, the game should just fire them on cooldown if you just hold down the fire button after initially spacing the AC/2 fire a tiny bit. The real reason I chose to go with AC2 on this build instead of UAC2 is because you run out of slots with UAC2.