Normally in halo, heavy weapons have one role to defend a location, or be picked up as a high tier power weapon. But that roll is a bit lack luster in both sides, sure it is fun but neither option is generally used that often except on Big team battles.
And that is where I got the following idea, to have turret mount points on BTB maps, these spawn with out a gun, but if a player bring a heavy weapon to them they can re mount the weapon, reloading it for another dismount or allowing them to use it as a 360 degree infinite ammo turret.
These would use a modular system where the bottom half has connection points for both traditional and plasma ammo a battery and an ammo drum..
Mounting the weapon would be a key prompt the same one as dismounting the weapon. Once mounted the gun will take some time to reload, once it is reloaded you can dismount it. While it is reloading you can use it as a point defense.
this idea is to give heavy weapons like chainguns, gauss turrets, rocket pods, and one would hope flamethrowers more staying power in the long run as you can head to a set point to reload them, even if this is a bit dangerous to do.