Cartridge Overall Length
Also: OAL · COAL
Total length of a loaded cartridge from the case base to the bullet tip. Constrained by magazine length and by how the bullet sits relative to the rifling.
OAL matters for two main reasons in a precision load. First, the round has to fit your magazine, since a cartridge that runs too long will not feed. Second, it determines how close the bullet sits to the lands of the rifling. Closer is generally more accurate, but seating too close raises pressure.
OAL is less repeatable than CBTO across lots because bullet tips can vary. For load development, measure CBTO instead and treat OAL as the magazine-fit check.