The bullet caliber mics at .355 and the bullet length mics at .511. The cartridge OAL that works for my P365 is 1.09 which is the recommended OAL in an old Lyman Handgun for Hornady JHP and works fine. I have gone down to 1.085, but then the fps raises enough where I know there is a pressure spike and rather than reduce the powder grain, I just left it at 1.09. I recently did a water jug test and I got a perfect \”nuke\” like in RMR\’s picture in the 1050 fps range. Hope this helps!!