Originally Posted by L473ncy
A Madbull 6.03 inner barrel and a Prometheus NEO Hop Up unit is what I'd go with.
Since you have an ICS why not buy two seperate uppers and the gear for them and change them up whenever you need?
agree fully on the second upper and front end.
this much easier solution since you have the ICS. when you want to play outdoors, swap in a 375fps spring and full cylinder combo and 500mm+ tight bore inner with a suitable outer and handguard. when your team wants you to play indoors, swap it back to you stock M4 setup.
just because your team plays all indoors, doesn't mean you can't show up at one of the posted outdoor games with out them.