I use a Vernier caliper to measure OAL and it works well. I use the Hornady case gauge with it to measure the shoulder dimension to make sure casings fit in my rifle chambers. It also works well and is not fragile.
Member: Orange Gunsite Family, NRA--Life, Varmint Hunters' Assn., ARTCA, American Legion, & South Cuyahoga Sportsmen's Assn.
Caveat Emptor: Cavery Grips from Clayton, NC. He is a ripoff