Anybody know if the F2000 flash hider will fit onto the FS2000? I'd like to shorten the barrel on my FS but don't want to necessarily go to the trouble of cutting and rethreading the barrel. The F2000 flash hider would shorten over barrel length an 1 1/2 in. I reckon. Also is that a little rail hanging off the bottom of the barrel on the F2000?