You'll notice more of a difference shooting a Non Magnum Load than the barrel length. Accuracy is Key, seeing the Animal is next and getting the shot where it counts is what matters most.
I do prefer a Longer Barrel only because Im 6'6" and I need a longer Mler, and it does add a bit of distance to your shot by burning just a tad more powder. It also helps to Stabalize the Bullet a little more too, but when you'r only talking a 1" or 2, then the effects are minimal.
(BP)