Is There a Difference in Ballistics Between .280 AI and .308?

Case Dimensions and Powder Capacity

The .280 AI has a shorter case length and a smaller case capacity compared to the .308 Winchester. This results in a slightly faster burning rate and a more compact cartridge design. The .280 AI case has a length of 2.015 inches, while the .308 Winchester case has a length of 2.015 inches for the standard version and 2.0155 inches for the long version. The .280 AI has a case capacity of approximately 44.7 grains of water, whereas the .308 Winchester has a case capacity of around 54.5 grains of water. These differences affect the overall performance and ballistics of the cartridges.

Ballistic Performance Comparison

In terms of ballistic performance, the .280 AI tends to have a flatter trajectory and quicker expansion due to its smaller case capacity and faster burning rate. The .280 AI typically generates a faster velocity, around 2,700-2,900 feet per second (fps), compared to the .308 Winchester’s velocity of around 2,600-2,800 fps. However, the .308 Winchester often produces a higher muzzle energy due to its larger case capacity and more efficient powder burn. These differences become more pronounced at longer ranges, with the .280 AI generally exhibiting less wind deflection and a more consistent expansion pattern.