I think you're better off merging 2 together, 4 would be extremely bulky. Would you be setting it up so all the turrets fire off in unison, or would 1 turret fire off 20, then the next fire off 20, etc?
I plan on going forward with merging all 4 of them together and have them fire simultaneously.
And I'd keep the trigger seperate. 40 rounds at once seems a little excessive. And too much of a pain to reload.
Like I stated ubove I will have all four fire at the same time, the working idea behind it is that I won't need to reload. This gun is made for rushing and taking out either one or more people in close-quarter combat. Then when all 80 rounds are depleted I'd switch to my secondary.
I think you're all forgetting (or never knew in the first place, which seems more likely) that the RF20 does not have a tank. It uses a bladder.
I would keep your bladders separate, though, and use 4 separate pumps. (one for each bladder)
I apologize for saying "tank", I'm well aware the RF 20 has a bladder I'm just used to saying tank. In hind sight I'm probably going to do just that and keep them seperate but instead merge the four pump handles into two handles.