Another thing to keep in mind when comparing BC’s is related to caliber. In general, heavier and larger caliber bullets have higher BC’s than smaller calibers, but not always. For example, consider a smaller caliber like a 6.5mm (.264 Caliber) 144 grain Long Range Hybrid Target that’s relatively heavy for it’s caliber, compared to a larger caliber bullet like a .308 Caliber 175 grain OTM which is absolutely heavier, but is relatively light for it’s caliber. In this comparison, the 6.5mm 144 gr bullet has a G7 BC of 0.336, while the 30 cal 175 grain OTM has a G7 BC of 0.263. In actuality, the smaller caliber, lighter-weight bullet actually has a BC that’s 28% higher than the larger caliber, heavier bullet.
Finally, if your goal is to indicate performance potential of a bullet at long range, you have to consider the muzzle velocity of the bullet as well as the BC. This brings the cartridge into the mix, and possibly a trade-off in muzzle velocity for heavier bullets. We cover this subject further in our next article, Form Factors.