Polish up the trigger, doing so w informed instructions for your rifle's trigger mech. Be careful with this and only follow trustworthy advice.
Try using a sandbag instead of the bipod pictured: it may be having some harmonics issues.
Experiment w different brands of ammo. If you handload, try different bullets and seating depths.
Try using the iron sights instead of the optics, to see if perhaps the optics mount is looser than the rifle. Use a precise and easily viewed target for, this, say at 100m.
Use fresh paper for each precise group.
Check to see you havent developed a flinch: unloaded, in prone position, no sandbags, get friend to put a dime on the barrel, and "shoot" as if at the range with live ammo. The dime should not fall off, if you hold steady. Do this a good 20 times at least.
Use a file and shave a very slight amount of metal off the gas tube assembly. It may be interfearing with barrel harmonics.
Remove the muzzle's flash hider. It may be interfearing with the harmonics.
Try wearing a thick winter jacket: it can some absorb recoil, but also change the length of pull from the stock.
POLITICS, WAR, ECONOMY, CONTROVERSY! and other heated discussions and debates in the PWEC sub-forum at the bottom of this forum main page. See you there!