The research I did while building my lastest rifle showed very little difference in accuracy or velocity in terms of barrel length. One report took a .300 win mag and shot it with the same load in groups of 3-5 shots(not sure what the exact number was). After each group they would cut off 1" of barrel. The results were amazing. There was virtually know difference in either accuracy or velocity until they got below 20". Even then the differences were not big, maybe a couple hundred fps. The big changes started below 18".

My objective was to build the smallest and lightest backcountry rifle I could without giving up both. I will try and drum up the article and post it.

Dave