BCPR shooters consistently shoot 2moa and under using black powder. I feel that with smokeless and "modern" actions/stocks/scope, you could approach 1moa.
The biggest problem is wind drift at long range. Bad enough with a 308, now do the same thing with a bullet going 1/2 the speed (twice the travel time).
There is a class out on the east coast for these cartridges. You may want to contact the NRA to get more info.