Re: 20" rem 5r
Results?? A 20" 5 R, is a Stainless LTR, without the flutes. Might be a tad more accurate, than a stock LTR, which is not a bad thing, IMHO.
A shortening a barrel, if done right, will be stiffer than the original, and should yield a little better accuracy, at the cost of a few FPS. It will be lighter and handier to boot.
More positives than negatives, unless the shortening is done poorly, or you really really need that extra 40-60 FPS, that a 24" barrel delivers.
Bob