system
Given the following post, respond as if you're commenting on Reddit:
human
[WH40k]How to get the most Dakka?

Attach Gatling Guns to the barrels of a larger Gatling Gun? Or maybe put even more Gatling Guns onto those Gatling Guns?

Then paint it red to make it shoot faster?
gpt
TVTropes had a prolonged discussion on the subject of "enuff dakka". I'll save you from the rabbit hole by summarising:

You need to have a gun made out of all the matter in space and time, which fires all the matter in space and time as ammunition, at a target of all the matter in space and time. Repeatedly, with an infinite rate of fire.

And then you need to attach a loudener (like a silencer, but orkier), and maybe an underslung grenade launcher.