re: A bullet out of an AR-15 travels 5 times as rapidly as a bullet shot out of any other gun

Ok let’s stoop to potato brain wave levels and assume the AR-15 produces the fastest muzzle velocity.

To say that it’s 5 times faster than every other gun is saying that every other gun produces the same velocity.

That dude is mashed potatoes at this point.

This info is easy to find and potato proves he is an idiot again.

LINK

Also barrel length effects it to and a regular AR is not the longest of barrels.

First, velocity. Longer barrels generate higher velocity because the propellant burns more completely. However, there are diminishing returns with extra-long barrels, depending on cartridge, caliber and propellant. It is often said we can expect a velocity change of about 20 to 25 fps per inch of barrel loss.

It is a well known fact you can dodge most bullets, but not an AR-15 bullet, it just flies too fast to dodge.