How deep does a 10mm Auto penetrate Water?

At the muzzle, a representative 10mm Auto load penetrates approximately 2275 mm (89.6 inches) into water.

What is the impact energy of a 10mm Auto?

This 10mm Auto load carries about 845 joules (623 ft-lb) at the muzzle.

Penetrates to ~90″ before stopping

Penetration depth

2275 mm (89.6″)

Impact velocity

380 m/s (1247 fps)

Muzzle energy

845 J (623 ft-lb)

Bullet behaviour

Intact

Fired at the muzzle, a representative 10mm Auto load (11.7 g, FMJ, 380 m/s) reaches roughly 2275 mm (89.6 inches) into water.

Water is a dense fluid medium; bullets destabilise and shed velocity quickly.