First of I'm hoping that I'm not posting this in the wrong part of the forum, pleas tell me if I have done that.
So I picked up Gun Haven 2 yesterday and while reading through it the Krime Cannon really cough my eyes.
10 DMG and -5 AP will do that.

This idea is base on a house-ruling/errata that the Krime Cannon should have ammo 6(C) instead of 6(M). This is based of this comment by jackpointer Fianchetto:
"The magazine capacity is limited, but the people that carry it tend to be able to carry enough magazines that it isn’t an issue..."Anyway, what if you added the Additional Clip and Fire Selection Change (BF) modifications to a Krime Cannon with a gyro stabilization for recoil compensation?
You would be able to fire 2 short bursts for 2 initiative passes before reloading. All this for just 18 200 nuyen

The gyro stabilization was the only way I could fine to reach RC 5+ and still be able to get both of the mods seeing as you can't mount a gas-venting system on a assault cannon.