My thought exactly. Yes, the bullet on the bottom, pointing to the right, was either fired from a musket (just kidding) or was in an ammo box or magazine or otherwise not fired from a rifle.

Still a pretty neat pic.

I also find the physics of it to be impossible if both bullets were traveling at high speeds from the barrel of a gun...how would the one bullet have the time to penetrate into the side of the other bullet if that bullet is also traveling at high speed? Wouldn't it simply just knock the bullet off course and not go through it?

There's a lot of disinfo memes yo distract... This has been posted over the past two years

Good observation. I first saw this photo decades ago and many times since and I never thought to notice that.

Probably in the dirt,or on the ground when hit.