That's the whole point; you can't get enough ammo in a 35 ton mech w/o either sacrificing a lot of stuff, or by making it a pure AC/2 mech. The whole point is to soften them up from long range, then move in to deliver the killing blow with medium lasers. For the record, here's what a pure AC/2 raven would look like;
Since you're going to be double-firing those AC/2s, I don't see a point in having an odd ammo count. Also, the JJs will probably be necessary to get this 'mech to a good, defensible perch. I'd rather run it this way. (I was tempted to keep 2xSLas for close-up defense, but it just wasn't worth it) http://mwo.smurfy-net.de/mechlab#i=35&l=91f4e3e3f472c267f2896dc31bc0d94c6fdcb7ee Compare that to a UAC/5 build which is faster, more heat efficient and has the same number of shots... but does far less DPS [REDACTED] Going crazy with the ammo makes it compare well to Cthulu Jr.'s other Balltistic Sniper Ravens. Edits: Removed my lackluster UAC/5 suggestion, added link to compare my recommendation directly to the post and the poster's other ballistic ravens.
I already did a UAC/5 build with both 1 and 2 UACs. I also did a gauss rifle build. All of them are under my "Optimized Ballistic Snipers" Category.
Reading... has never been my strong suit. Edited previous post for clarity and tried to stay more on topic.
