Denoting a 2.800" COAL,less throat geometry is moot...though 308's Remmies are long throated like Linda Lovelace,so the best move is always to crowd mag confines to minimize their leap to the lands.
As per he initial query and assuming a modicum of thought,the throat had better been cut with far more thought than that or all quickly becomes moot. A barrel can be no better than it's throat or chamber.
Though admittedly,'15 is always the ticket in the 308...................