In our quest for accuracy there are two dynamics which sometimes confuses the issue. The first is, "What makes the rifle accurate?" and the second is "What makes the rifle easy to shoot accurately"
Perhaps our first job is to define accuracy. The hunter and the bench rest champion may have very different requirements, but let us agree that accuracy can be described as the potential of a combination of rifle and ammunition to deliver a cold barrel shot on the target, and the potential to put a number of subsequent rounds in close proximity to the cold barrel shot, regardless of external influences of local weather conditions, elevation, or the negative influences of the shooter on the combination.
Those things that make a rifle accurate include; a chamber that very closely matches the dimensions of the loaded round, the length of the lead with respect to the choice of bullet, a barrel with uniform interior dimensions, barrel weight appropriate to the number of rounds to be fired in a string, a bolt face that is square to the barrel, stock material that is stable in a broad range of environmental conditions, bedding that is appropriate for the style of receiver and weight of barrel, the precision with which the components of the rifle can be assembled and bedded into the stock, uniform ammunition appropriate for the job at hand, with bullet weight appropriate for the barrel's twist.
Those things which make the rifle easier to shoot accurately include; a trigger which has a crisp break and light let off with no appreciable movement, fast lock time, an ergonimic stock that fits the shooter and when proper cheek weld is attained, aligns the eye with the sight, a sight that allows the shooter to see the target and provides contrast between the aimning point and the target, and the sight must be easily adjustable with predictable movement, but robust enough not to move during the course of firing.