Do heavier bullets always penetrate better in .308?

Bullet Weight and Penetration

When it comes to penetration, bullet weight is just one factor to consider. In .308, heavier bullets can provide greater kinetic energy and thus deeper penetration, but only up to a point. For example, a 168-grain bullet at 2700 ft/s will penetrate deeper than a 150-grain bullet at 2600 ft/s, but a 180-grain bullet at 2600 ft/s may not penetrate as deep as the 168-grain bullet.

Muzzle Velocity and Twist Rate

Muzzle velocity and twist rate also play critical roles in penetration. A faster twist rate may be required to stabilize heavier bullets, which can reduce their overall penetration. For instance, a .308 rifle with a 1-in-10" twist rate may be better suited for 168-grain bullets, while a 1-in-12" twist rate might be more suitable for 180-grain bullets. On the other hand, a slower twist rate can cause heavier bullets to tumble, reducing their penetration.

Bullet Design and Construction

Bullet design and construction also significantly impact penetration. For example, a bullet with a soft point or hollow point may penetrate deeper than a solid, copper-jacketed bullet, as it is more likely to expand and transfer energy to the target. Conversely, a bullet with a hard, copper jacket may not expand and therefore may not penetrate as deeply as a softer-pointed bullet. When choosing a bullet for deep penetration, consider the design and construction in addition to weight.