Just do a multiple inner barrel set up: 1 long one(590mm tightbore) for outdoor range, and a smaller less than stock or however you want your indoor setup, mine is about 340mm. All you need now is a full cylinder, silencer or however you want to attach to your outer barrel to cover the extended barrel, and then upgrade internals as desired.
There is a trick here, my SPR runs 390FPS for my 590 barrel outside, but without changing anything other than the inner barrel to short length, I drop about 100FPS to about 300FPS for an indoor game. If you can figure out this trick, your good to go for both indoor and outdoor games without having 2 guns.
Draw aggressively, shoot decisively, holster reluctantly.
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