The OP is looking for something to kill with (ie. Hunt & plink), this thread isn't a what barrel length can get me the best velocity in a 6.5x47L thread. I can attest, that with the short 16.5" barrel of one of my 6.5x47L's I have accomplished both COMFORTABLY & RELIABLY on numerous occasions.
Can you get more velocity out of a longer barrel, YES.. Is it more cumbersome to maneuver a longer barrel in tight quarters (ie. a blind, hunting shack, tree stand or hide) YES!
Will the shortest of the short barreled 6.5x47L's perform with more than enough horse power for the intended purpose... YES!
WITHOUT A DOUBT, IT HAS & I'VE DONE IT!
For all intended purposes, would you be willing to take a dose of 136 Scenar at 1200 yards to the chest from a 16.5" 6.5X47L? I WOULDN'T!!
Believe me, I have administered my fair share of pills on game & AR500 with this rifle & I have seen the results with my own eyes!
This 16.5" 6.5x47L quickly became my "go to" rifle and always finds its way into the trunk of my car on EVERY shooting session I attend. I can certainly say that out of all my custom rifles this one gets the most use. As a matter of fact, I had it out this afternoon messing with 123 AMAX's & Varget. (For ground hogs out to 300 yards). Velocity readings to follow on Monday..