Part 4 of A Ballistics Guide for Geeks, Writers and Geeky Writers: Terminal Ballistics

A Fired .38 caibre Hollow Point round, completely expanded and deformed after striking its target. From Wikipedia, by user Rickochet

Welcome back! So far we’ve talked about the flight of projectiles, and how things change as our projectiles and the atmosphere around them change.  Now lets talk about what happens to our projectiles when they actually impact with something!

These projectiles that we’ve thrown have now flown from their projector to the other end of their ballistic trajectory.  Eventually, they’ll hit something other than the medium they are flying in.  Wether it’s the intended target, something that happens to be in the way, or one of those weird bubblegum asteroids those Sci-Fi writers keep dreaming up, something will happen. Continue reading

Part 3 of A Ballistics Guide for Geeks, Writers, and Geeky Writers: Stability and Recoil

Welcome back all!  In last week’s episode we talked about external ballistics, and the forces that affect a projectile in flight.  We also talked about those same projectiles flying around on Mars, in outer space, and on planets made of bubblegum.  This week we’ll discuss stability of a projectile, and the things we can do to limit the effect those forces have on the projectile’s flight.

So what can we do to help them out? obviously we want to hit our target and Mother Nature (or other resident natural deity on whatever sci-fi world you’re writing) is doing her damnedest to make sure we miss.  We have to find some way stabilizing our projectile, to make it less susceptible to outside forces.  Here’s what would happen if we fired a projectile with no means of improving stability, as it flies, minute disturbances and inequalities in forces applied cause it to tumble.  This video comes from YouTube user vidaday, and is awesome.

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An Introduction to Ballistics for Geeks, Writers, and Geeky Writers: Part 2 of Many

Welcome back!  Today, let’s talk about external ballistics.

Bullet coming from S&W by Niels Noordhoek

Anything and everything on earth is affected by gravity.  Objects fall towards the earth at a constant rate, known as the gravitational constant (9.8 m/s²) .  I hear those sci-fi writers again.  Yes, if we were on the moon, or Mars, or somewhere else, that constant would be different, and the ballistic flight will be different, but let’s get there in a bit shall we?  Impatient Sci-Fi writers!  As a quick reference, Moon Gravity is roughly 1/6th that of earth, and Mars is roughly 1/3. Newton tells us that an object in motion remains in motion unless acted upon by an outside force.  So in a theoretical, gravity free environment, the projectile would just keep going straight, in the last direction it was propelled. Of course, Gravity isn’t the only thing that affects a projectile.  The medium it flies in also plays a big part, by adding drag.  The air itself slows the projectile down.  In a vacuum there would be no aerodynamic drag, and the projectile would keep its velocity, until acted upon by something else.

That Newton guy is everywhere isn’t he?

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