The accuracy and reliability of a gun are inherently contradictory. To enhance the precision of a gun, you inevitably sacrifice its reliability, and to achieve high reliability, precision is bound to be impacted. At least with current technology, a balance must be struck between the two to choose the most suitable point for oneself.
Making everything extremely precise improves accuracy, but the tolerance decreases, inevitably affecting reliability. Conversely, making a gun less precise makes it easier to manufacture and very reliable, but accuracy is necessarily compromised. These two gun-making concepts are most clearly exemplified in the gas-operated M16 and the long-stroke piston AK47.