I'm typing this from my phone so I hope it's not a repost. I need an expert opinion. I was planning on buying a complete upper from a certain company with 16" barrel and carbine length gas system. The local "experts" started telling me that for a 16" I need to run a mid-length gas system. They went on to tell me that the carbine system is too hard on the rifle. I didn't really get specifics because I thought I was being messed with but something was said about a heavy duty buffer among other things. This particular rifle will be for HD and occasional recreation target shooting.