C.O.A.L vs Ogive Measurements

We get asked all the time why we advertise COAL (Case Overall Length) measurements and do not provide Base to Ogive (BTO) measurements. Simply put, it is because each brand of ogive tool takes its measurement from a different point on the projectile and the measurements DO NOT transfer between brands of tools. Whereas, anyone with a caliper can measure and clearly understand COAL measurements then use their own tools to record BTO if they please.

In the example below, we can see that someone has measured and provided a BTO measurement written on this dummy round of 2.170″. However, as you can see, the Hornady tool in the picture is showing a BTO measurement of 2.228″. That is 60 thousandths difference! If they had said the COAL is 2.800″ for example, everyone would be on the same page and it wouldn’t matter that we have different tools.