Stubbleduck, that thing about barrel length efficiency for various RF ammo has always been a puzzle to me. What you stated ref. short and LR barrels sounds perfectly rational...but in days past my chronograph had a different opinion. The CB shorts from my Contender run in the range of 780 fps. Ammo lot? Match chamber? Don't have a clue myself. From a Rem 572 with a 24" barrel the statistical difference was nil. To muddy things up a little more a pair of Rem 513s w/ 26" barrels are about 50 fps faster than the same loads from a 10/22. All 3 rifles have factory barrels.
Have seen the same thing with CF rifles of course and that is easier to grasp. RFs can be a puzzle sometimes.
