i reccomend for your nailgun to at first use the blue variant then switch to the green right after shooting(this will fully build up the meter for the green nailgun) then switch back to the blue nailbun fire a little bit then back to the green and repeat(this should cause the meter on the green one to never end letting you shoot it for a lot longer than your could at base though if the meter ever goes back to 0 then it will stop though you can just do it again with your second charge) Edit Also first comment gang
i reccomend for your nailgun to at first use the blue variant then switch to the green right after shooting(this will fully build up the meter for the green nailgun) then switch back to the blue nailbun fire a little bit then back to the green and repeat(this should cause the meter on the green one to never end letting you shoot it for a lot longer than your could at base though if the meter ever goes back to 0 then it will stop though you can just do it again with your second charge)
Edit
Also first comment gang