RE: How important is barrel length?
My step dad used to compete at the state level in benchrest and I competed as a young teen on the regional level in both centerfire and rimfire benchrest. I have been to one or two competitions.
I have seen pistols with 12 and 14 inch barrels pull off some amazing groups with a centerfire action.
Some of the rail guns have extremely short barrels as well and are VERY accurate.
Paul