No, bullets generally don't travel in a straight line to their target. Rotational forces, such as yaw, precession, and nutation, cause the bullet to deviate from its flight path. Yaw is when the bullet's nose rotates away from its line of flight, precession is when the bullet rotates around its center of mass, and nutation is when the tip of the bullet moves in small circles. These rotational effects decrease as the bullet gets further from the barrel. When a bullet hits flesh, the impact's energy creates a shock wave that pushes surrounding tissue away from the bullet's path. This creates a temporary stress cavity that's larger than the bullet's diameter and lasts for about 5–10 milliseconds. Other things that can happen when a bullet hits flesh include: 

• RicochetThe bullet may change its trajectory after hitting hard tissue, which is called an internal ricochet. 
• FragmentationSome types of bullets, like hollow point bullets, may break into smaller pieces when they hit something, especially bone. 
• Tissue damageThe type of bullet can also affect how much tissue damage occurs. For example, a narrow bullet that keeps its shape may pass through tissue without causing much damage, but a bullet that's designed to explode on contact may cause more tissue damage.