As some previously mentiond, the COALs given are often predicated on the maximum cartridge length which will fit in a minimum magazine, nothing else. The optimum COAL for a specific gun may well be longer than some handbook's maximum COAL.

Most really serious rifle shooters have ways of determining the best COAL. There are ways to determine the maximum COAL for a specific bullet and rifle which allows the bullet to just touch the rifling. The optimum COAL for best grouping is a little less than that. Not so easily done for handguns, However, determining the best COAL is probably the single most important factor in getting the best grouping performance.