Thanks! With the information in the article you just linked, I am now very suspicious that this is a picture of the bullet, where I previously thought it was plausible from my low-precision estimate. From the article:
“If the gunman was firing an AR-15-style rifle, the .223-caliber or 5.56-millimeter bullets they use travel at roughly 3,200 feet per second when they leave the weapon’s muzzle,’’ Mr. Harrigan said. “And with a 1/8,000th of a second shutter speed, this would allow the bullet to travel approximately four-tenths of a foot while the shutter is open.”
Same procedure, but an AR-15 shoots a bullet faster than the speed for a generic bullet that I used, and the shutter speed was faster because it was a fancy NYT camera. 3200ft/s is almost exactly 1000m/s. The 1/8000s shutter speed is the fact that seems the most reliable, assuming that the photographer knew what setting their camera was on.
What I disagree with is that that streak is only 0.4 feet long. The average size of a human male head (brow to back of head) is about 20cm, or 8in per this image from Wikipedia. The streak from the bullet in the image is about twice the size of Trump’s head, or 40cm/16in. Due to projection effects, this is a lower bound on the path of the bullet during the 1/8000s exposure. This puts a lower bound on the speed of 3200m/s. This is over three times the velocity of an AR-15, at minimum. Either this was some super-high-powered rifle to fire the bullet that fast, the shutter speed is misquoted (or a misleading representation of the exposure time), or this isn’t picture of the bullet.
Thanks for providing the data to make me suspicious that this is an image of the bullet.
