I saw a recreation of the Kennedy assassination on the Discovery channel the other week.

To see how much a bullet deforms, they shot it through a log at very close range(a few yards.) The bullet was relatively undamaged when recovered, in fact it looked almost pristine.

When they shot a simulated human torso at a distance of 70 yards or so, the bullet struck a "bone"(I believe it was a pig's bone.) The bullet deformed quite a bit.

My question is: why does a bullet deform to a lesser degree when fired at very close range into wood than it does from glancing off a bone at much greater distance?

Probably because wood is less dense than bone. Or at least most wood.

Quoted: I saw a recreation of the Kennedy assassination on the Discovery channel the other week. To see how much a bullet deforms, they shot it through a log at very close range(a few yards.) The bullet was relatively undamaged when recovered, in fact it looked almost pristine. When they shot a simulated human torso at a distance of 70 yards or so, the bullet struck a "bone"(I believe it was a pig's bone.) The bullet deformed quite a bit. My question is: why does a bullet deform to a lesser degree when fired at very close range into wood than it does from glancing off a bone at much greater distance?

The bullet had an opportunity to yaw (turn sideways) going through Kennedy & Connally.

The bullet fired into the log never yawed...it remained point-forward, so it didn't get squeezed like a tube of toothpaste in its penetration