Noticed there wasn't a mod for this as far as i know, so said what the hey I'll upload it.
If you're like me, and thought the whistling sound after you fire the railway rifle is kinda "Meh", well lets get rid of that whistle entirely!

Make sure you've done this step beforehand
Go to Documents\My Games\Fallout4 open Fallout4.ini
Find where it says sResourceDataDirsFinal=STRINGS\
and make it look like this sResourceDataDirsFinal=STRINGS\, SOUND\,