If you have a cleaning rod and a set of calipers, you can now determine the optimum OAL for any bullet in less than two minutes with the help of Frankford Arsenal's Cartridge Overall Length Gage. This simple kit consists of two clamps that easily attach to any cleaning rod, 1/4" in diameter or less. Works on all rifles.
Simply install the appropriate size tip on the end of your cleaning rod, insert the cleaning rod to the bolt face, install one clamp, remove the bolt, and drop in a bullet (projectile only) into the chamber. Hold the bullet against the rifling with a pencil, touch the bullet tip with the cleaning rod tip, and install the other clamp. Next, measure the inside distance between the two clamps with a calipers and record, or use as a gauge to check the seating depth set-up during your reloading sequence.