It is not going to happen since it would require too many changes to all sorts of mechs but I would like autocannons more if they weighed less and some other benefits.
There is no way current ACs are going to be resized. It would invalidate too many designs.
What could happen is a slight reworking....
For example, the idea that an autocannon can have a "slow" rate of fire should be dropped. You want that type of weapon, there is the Gauss, and we could create a new modern Rifle. Autocannons should be just what they are stated to be - rapid fire weapons that fire a burst of shells. That way, the mass can be explained away as the mounting, feed mechanism, cooling systems and anti recoil measures designed to keep the weapon on target during the burst. You'd probably want to specify something akin to an AC/2 firing a ten round burst.
Now, that isn't to say that ACs couldn't be -as the title says - tweaked. But it would have to be rules based becasue otherwsie, the only other option is to design a brand new weapon.
So - what could be done if the weapon stats cannot change?
Ammo - this could be a potential penalty. Ammunition amounts would drop. Doesn't change the mass, doesn't change the crits. Just means fewer shots per ton. Would an AC/2 that gets 10 shots per ton of ammo be of interest to anyone? Probably not. Unless there were changes to go with it. Of course the problem with changing ammo amounts are the changes necessray to the record sheets.
So - what rules change could be done to make ACs more "viable" if the stats cannot undergo major changes.
1 - ACs use ADL ammo. In short, the weapon can choose between flak, standard and flechette rounds at will.
2 - All ACs use the same ammunition and can draw from the same bins. Say - each bin provides enough ammo for 15 damage. You fire an AC/2, you use 2 points worth of ammo. You fire an AC/20...you fire 20 points of ammo. Yes, with these specific values, you'd need two tons of ammo which would break a couple of designs but this is simply to illustrate the concept. Again, record sheet issues, but a simple rules change stating all AC ammunition bins give x shots per ton might be, but probably isn't, viable.
3 - There is no such thing as "precision" ammunition (except possibly for older model ACs which lack the appropriate firecontrol). All ACs get a -1 TN bonus. Caselss ammo is standard.
4 - ACs can be downgraded to the same range and damage as lower class ACs....an AC/5 can act as an AC2/ and AC/20 can act as an AC/2, AC/5 or an AC/10.
5 - ACs deal triple damage vs buildings, half damage vs Mechs and modern combat vehicles, full damage vs support vehicles and conventional infantry. We could have lasers do half damage vs buildings for even more differentiation.
6 - ACs can fire twice per round, with a targeting penalty.
7 - ACs might be able to get away with a slight reduction in mass of between 0.25 and 2 tons, which could then be spent on ammo. Maybe each 0.25 tons gives you 3.75 shots of ammo.
8 - Different fusing and spread options to allow for indirect fire and AOE effects - miniature on board artillery.
Or whatever. Tweaks to ACs, if desireable, have to come via the rules. Those are a lot easiee to change that dozens of AC using designs. The size and base power of the weapon cannot change and while there is some leeway with mass, there isn't a lot. That implies increasing the weapons flexibility, or making it specialise in certain roles.
Lets say these concepts were used for ACs.
ACs would be just as heavy as they are now.
Just as large.
But more flexible, more accurate, able to adjust to different targets, able to act as weak artillery with a specialisation of anti-fortification
But the down side is that they have a much shorter battlefield duration. Ammunition would be large, heavy, expensive and ACs fire a lot of it.
