I just recently invested in this gauge. I am having a little trouble understanding exactly what the measurements may mean about my chambers/throats other than the obvious that I need to load a little shorter than these measures and no more than max COAL. All these measures were made with calipers with the bullet in the Hornady modified case. The bullet is a 168gr hpbt: Springfield M1903: 3.317" HRA M1 Garand: 3.386" Browning A-Bolt: 3.300" What do these measures mean in regard to my chamber/throats? If my understanding is correct, the M1 appears to show some throat erosion. Other than that, the 1903 and Abolt are shorter than the max OAL given in several manuals. Now, I know that the manual's given OALs are just what was tested in that particular gun, but what does that mean for both of these guns having shorter max lengths? I never realized how useful this tool could be as I would hate to have loaded a bunch of rounds that exceeded these measurements.