Is the benefit of 14.5" over 16" barrel length so much to make it worth it to SBR a lower or deal with the pain that comes along with pinned/welded muzzle device? What real benefit does the slightly shorter length give you? I don't have experience actually fighting inside structures, but my gut feeling is that if I were going to be fighting in a predominantly urban area, I'd grab my 11.5 on either an SBR, a pistol lower, or a machine gun lower, depending what I had on-hand.