I love my 6.8
getting 2800 FPS out of a 16" barrel and 110g barnes TTSX, sub MOA rounds and it's a new upper
my previous was an 18" mid weight stainless barrel (new one is lighter and is a lothar handlapped chrome lined)
the 18 would shoot 1/2" groups, 3/4 and under all the time
I am a big fan of AR15performance.com's work and products
I killled 3 Texas whitetails and 3 hogs with it this past year
I think of the 6.8 as a 270 short
now, with the 85g Barnes they are getting close to 3200FPS out of a 16" barrel
that's 243 velocity
I haven't tried any yet and the 110 barnes TTSX or prohunters work great
the latter would be fine for deer and fine for hogs though I prefer the TTSX just in case I hit shoulder and close range I KNOW the bullet will expand and punch clean through even big hogs
I would say 400 is pushing the limits a bit and will certainly kill deer with perfect shots, Harrison at AR15Performance killed an Elk at 400 with one...
my 6.8 is setup with a 1-4 Trijicon Accupoint scope and is what I use for stalk hunting deer and hogs and if I am going to hunt hogs at night over a feeder, usually around 75s away and I have illumination
sitting in a stand expecting 300+ yard shots I would take my 270 with a 3-10 scope
I love my little 6.8, it's compact, light and lethal.. and with a 2 point sling carries WAY better than a regular rifle with a standard sling setup.. it's right there, across my chest with the muzzle pointed down and to my left and is fast to deploy.
bipod is there just to make the pic easier to take