I'm no expert on precision rifles, however from what I have read and researched, a shorter barrel, only reduces velocity and not accuracy. There is a popular belief that shorter barrels actually increase accuracy, as the barrel is more rigid and less inclined to whip. I have also read that shorter barrels reduce barrel harmonics, but that is way to far into the physics department for me to understand. I can say that the Rem 700 20" LTR I previously owned was quite accurate with factory match ammunition. Considering that I rarely shoot beyond 300 yds, and that I was doing a bunch of other accurizing work to my rifle anyway, I felt that there was really no harm in reducing the barrel length. So to summarize, you'll have greater bullet drop due to decreased velocity, but should maintain or marginally improve the accuracy of your barrel. There are precision rifle gurus on this forum, that will surely know more about this than I, and my chime in at any time.