The 10 mm Auto cartridge has a reputation for deep penetration, and many 10 mm loads rely on robust bullets to survive the high-impact velocities. If you have a 10 mm, but want to limit over-penetration concerns, DoubleTap has the answer. By driving Nosler's 135-grain JHP bullet at more than 1,500 fps, there is massive fragmentation. The result is a 10 mm load that does frightening things to a gelatin block. Penetration is limited to less than 10 inches, regardless of barrel length.