The mystery of how a bullet from a 14.5×114mm round ended up in an Afghan soldiers head without killing him has been solved. It turns out the round was not fired from a gun but was used as shrapnel in an IED. It would have been travelling much slower, and probably tumbling, when it hit the soldier. Sprites.com has interviewed the surgeon and anesthesiologist who performed the operation.
I had struggled to believe that a bullet from a 14.5×114mm round would fail to cause fatal damage to a man’s head. The large caliber, armor piercing and heavy bullet would have had to have used up almost all its energy to not cause a fatal wound. Bullets usually hit the ground before they slow down to 0 fps.
According to my back-of-the-envolope calculations, at 1.8 miles (3000 yards) a bullet from a 14.5×114mm will be travelling at around 1000 feet per second. It will have dropped hundreds of feet from the point of zero. The energy contained will exceed 2000 ft/lbs. Being hit in the head by this bullet at 3000 yards will cause far more damage than a .223 / 5.56mm would at the muzzle!
I believe the doctors are using the term ‘high explosive round’ incorrectly. The x-ray looks constant with Amour Piercing Incendiary (API) bullets. API bullets contain white phosphorus (or equivalent substance) in the bullet nose. White phosphorus burns rather than explodes.
A high explosive round would contain a secondary high explosive inside the round with a primary primer/detonator in front (see above image). The primer mechanism would be visible in the x-ray. It is far more likely that bullet is API or API with tracer. Regardless, white phosphorus burns easily and if it was ignited it would cause a lot of damage to the patient and doctors. The precautions the doctors took were necessary.
[ Many thanks to Tony for solving the mystery. ]