I would be willing to bet the target can't tell much of a difference. However you will have an easier time selling the 5R due to the "MilSpec" black magic.
5-R mil-spec has a "5-R" barrel five lands and grooves. Lands have a 45 degree angle from the bottom of the groove to the top of the land........... Or they should. Brother recently picked up a 5-R 308 and I landed a 223, barrels are better than your average Remington and they shoot. If I was out to just grab a stock Remington it would be the 5-R.