Faster Than A Speeding Bullet?

Factual Questions
1

Hey! So, how fast IS a speeding bullet?

Obviously slower than light, but slower than sound?

How fast is a slowing bullet? or a bullet not speeding or slowing, but just moving at normal speed?

Thanks! This will be helpful in case I ever need to outrun a certain man in red and blue pajamas.

2

Depends on the bullet and the cartridge. Muzzle velocities can range from ~300 fps to well over 3000 fps. For reference, the speed of sound is 1080 fps at STP.

3

To expand on QED’s answer, many (if not all, I’m not sure) pistol rounds are subsonic (slower than sound), whereas a lot of rifle rounds are supersonic. See here. That sight lists the “.220 Swift” as the fastest rifle round, at 1220 meters per second.

4

From this article on the Colt 1911 .45 pistol. So, clearly not all pistol rounds are subsonic.

5

Actually SPOOFE the .17 caliber Remington rifle is a real screamer at 1250 meters per second. Okay the Swift is damned fast too, but I think the .17 holds the record for conventional firearms.
Usually .22 caliber bullets travel at the speed of sound, though there are some sub-sonic ones.

6

Answers:

  1. >500 feet per second (although 400 fps is still wicked fast)
  2. Often slower than sound, but rifle bullets exceed Mach 1 regularly <see below>
  3. Constantly slowing, due to air resistance. Rather, it is at top speed at the muzzle, it is decelerating quickly after it leaves the muzzle, and the deceleration “slows” every moment it’s airborne. Until it hits, when deceleration is completed within a very short time.
  4. Superman is not real.

A bullet exploding is loud enough on its own (left on top of a hot plate, for instance. Don’t do this, even if you’ve got a convenient brick wall - ricochets are still dangerous). A good rifle shot is much louder because the bullet is traveling faster than the local speed of sound, creating a sonic boom at its leading point and trailing edge. Since the bullet is short you just hear a single noise for all three sounds - with the Concorde you can actually hear both booms.
If you are somewhere in the direction the bullet is fired and some distance away from the gun (in battle or in the sights of a stupid hunter), you can hear the boom (more of a crack) before the shot.

7

buh, meters. me make NASA joke.