UPDATE thanks to Soliddew, the right hand shotty going off when you right click while holding an object should be fixed.No more accidentally obliterating your turrets with your itchy trigger finger that forgets the use button is also there, like I did. A lot.
Anyway check out his Jukebox mod - https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3474269279

Slight update, added means to stop a graphical glitch when surfacing in water due to the new swimming functions.

UPDATE - Thanks to Soliddew there is now a designated spawn point for the shotguns.
Check discussion for location.