Looks like your getting much better performance out of the stock handle than I am on my .308, I swapped out the Shitty Plastic Stock for a HS precision with the ali bedding block and walah instant 1/2" groups. Looking and sniffing for an economic alternative now, might need to have a look at Boyds...
Check the pressure points along the barrel and set it free floating. Same happened to mine until i took some sandpaper to it. Now doing just damn fine.