Where are you resting the rifle when you are benching it? Are you resting in on the end of the forearm? That would normally be just fine but if you are having a stock problem (and you may be) it may be making things worse. I would do 2 things now.
#1 Remove the rifle from the stock and investigate why the barrel is not free floated there. As mentioned previously, a pressure point can be designed there or it could be another problem like the the tip of swivel stud touching the barrel or the barrel channel being to narrow. Look at the underside of the barrel - any shiny spots?
#2 Shoot it again w/ some good quality ammunition, this time resting the stock just forward of the magazine floorplate. If the stock is causing you problems due to barrel impingement at the fore end, groups should improve by moving the resting point to the rear (the solution then is to work on the stock - this is just to help diagnose the problem).
It is not unusual for a factory rifle to have a rough bore that can contribute to poor accuracy. Usually, about 200 rounds need to go down a bore before it's shooting it's best. I think your rifle should be performing better than it is right now, but this may be contributing.
Bench technique: Rest the forearm of the rifle on a solid, rest trigger hand pulling the rifle rearward into the shoulder but NOT torguing the pistol grip. Unlike a shotgun, use just the pad of the index finger on the trigger - do not wrap the trigger to the 1st joint. Off hand should be under the rear of the stock grasping the rear bag - NOT touching the rifle. Rifle is pulled gently but firmly into shoulder. You are comfortable but not leaning or resting on the rifle or applying excess pressure to the rifle from the pistol grip or from the cheek weld. Line the crosshairs up in the center of your bullseye, take a deep breath, gently release about 1/2 of the breath and hold. Gently squeeze the trigger w/ the pad of you finger until the sear releases. Focus on being able to maintain the sight picture of the crosshairs centered in the bullseye even through the shot fired (you won't be able to - too much recoil, but you should still try for each and every shot).
hth
David