You are only showing a selected angle.
Oh, but it most certainly is. It sustained no deformation in passing through flesh but it did have its velocity reduced. It began tumbling upon leaving Kennedy's neck and by the time it struck Connally's rib it was somewhat side on. That is what caused the longitudinal flattening that we can see on the bullet. By the time it struck Connally's radius bone, the bullet was travelling at below its deformation velocity. It was enough to fracture the bone but not enough to deform the bullet.
The above bullet had been fired into a human wrist during tests by Failure Analysis Associates in 1992. They had reduced the powder charge in order to decrease it's velocity.
"The test bullet was non-deformed. It was not flattened in the least and had nowhere near the damage of CE 399." -- Dr. Martin Fackler (Live by the Sword, by Gus Russo)
They don't know the exact velocity that CE399 was traveling at when it hit Connally's wrist. They approximated it to be 900 f/s. That approximation was made after a series of tests. The Fackler bullet was traveling at 1100 f/s.