This whole barrel length vs. accuracy thing is starting to give me night sweats! Until recently I had assumed that shorter and stiffer and so, smaller amplitude vibrations = better accuracy. After looking at experimental results for this and my own recent experience, I am convinced it is way more complicated than that. For example, I built my own 35 whelen bolt gun starting with an old Savage 110 action. I ended up cutting the after-market barrel down to 21 inches to balance properly in an old Savage wooden stock. I even bedded the action, lug, and the rear of the magnum contour barrel. Result - with my most accurate handloads, no better than 1.5 inches (3-shot groups) at 100 yards. So...I like the idea of making guns lighter, so I bought a Boyd's featherweight thumbhole stock. Nothin bedded - result: same load, one ragged hole at 50 yards, under an inch at 100 yards with consistency. As far as I can tell, it is just the way the new stock fits - the way it holds on to the recoil lug, how it touches along the barrel, etc., that makes the difference. If you can do it - I think the best thing is to just find the barrel length that works best for your particular gun. If you want it short - you may have to try a couple of short lengths to find the sweet spot (start longer and work down, of course) - or a change in stock, a change in forarm pressure, or one of a number of other things may be important to accuracy. Not sure there is an easy answer to this question.
