Tuesday, January 23, 2024

Speed of sound.

A writer friend and I were talking a while back. He mentioned a book he had read in which a character under fire heard a bullet strike a tree, then heard the report of the rifle. My friend suggested this was unlikely, as the speed of sound is much greater than that of the bullets of the era—the Old West.

I disagreed, and we left it at that.

However, curiosity got the best of me, so I thought I’d do what they tell you to do on Sesame Street: “Look it up.” It took a few hours and lots of mouse clicks to reach a number of relevant web sites. Here’s what I learned about the speed of sound and the velocity of bullets fired from a few rifles in common use at the time in question.

Sound travels through the air at 1,125 feet per second. That varies somewhat, affected by temperature, humidity, and wind. And, of course, sound waves dissipate and the noise fades with distance. The velocity of bullets varies as well, depending on wind and distance, and the bullet loses speed the farther it travels.

But, all things being equal, a bullet fired from a .52 caliber Spencer repeating rifle would lose the race, lumbering along at a paltry 931 to 1,033 feet per second.

The race with a .44 caliber round from a Henry rifle would be a dead heat, the bullet leaving the barrel at 1,125 feet per second.

A bullet from a Winchester .44-40 Golden Boy outruns sound at 1,433 feet per second.

The old-time Hawken rifle, .50 caliber model, spit out lead at 1,600 feet per second.

Winning it all is the Sharps .50 caliber, which, depending on grains of powder in the cartridge, fires bullets that fly 1,448 to 1,814 feet per second.

None of which matters. But how else is an old man with no gainful employment supposed to spend his time?