Q&A: The Physics of Recoil and Science Fiction Guns

I’m creating sci-fi guns. Is it possible to simply say this gun is pretty much has no recoil? In fact, what causes recoil? Could some advance tech simply doesn’t have recoil or recoil cushion kind of thing? Also is it ever possible that huge guns have little recoil and tiny guns with huge recoil? Or big guns with little power and tiny ones with huge power?

So, as the second question, it’s Newtonian physics. Specifically, “for every action there’s an equal and opposite reaction.” Recoil experienced by the user is the result of the powder burn in the chamber. Often times, it’s partially mitigated by mechanical considerations in the gun, but at the same time, bolt travel can also contribute to experienced recoil.

Recoil compensation systems exist. These can include gas vents designed to counteract climb, mechanical buffers, and counterweight systems. Part of the problem with recoil management is, simply, the technology we’re using (and have been using for over a thousand years at this point.) When gunpowder burns, it causes gasses to expand rapidly in all directions. This is what propels the bullet down range, but also applies force to the user.

(And, yes, that over a thousand years. The first firearms date back to the 12th or 13th centuries, but the use of gunpowder in China dates back to the first millennia.)

So, even with modern technology, you can significantly reduce experienced recoil. Some of this is physics, but you can redirect that force, though you still have to deal with it.

So, can you do away with recoil entirely? Technically, probably not, but you could potentially reduce it to the point that it is undetectable by the user.

High energy weapons, such as lasers, plasma projectors or particle beams technically would probably have at least some theoretical degree of recoil, even if it was just from the user pulling the trigger. But, we’re not talking about enough to be meaningful. Gauss weapons would probably also have some recoil from accelerating the physical projectile, but in comparison to dealing with burning powder, it’s mild enough that t you could (probably) mitigate perceived recoil entirely.

As for the question of big guns that are weak, why would you do that to yourself? A larger weapon will be more awkward to carry, more difficult to use, harder to manage when not in use. There’s really no point here. You can, technically see this, with antique artillery pieces, which are inferior to their modern counterparts.

That’s the one time when I could legitimately say you might something like a big, heavy, gun that’s underpowered. If it’s technologically inferior to more recent developments.

As for powerful small guns? Yeah, that’s a thing that can happen. Especially when you’re comparing more modern weapons to older ones.

This gets a little awkward because there’s no meaningful way to quantify damage output from firearms. Even a musket can kill you. It’s a question of what the bullet damages. The real advancements have been to things like range, accuracy, capacity, the ability to quickly reload, and long range optics.

A modern subcompact Glock is considerably more lethal than a Napoleonic era musket. But, that’s not because the bullet itself does more damage (in fact it might not.) It’s because the pistol is effective at ranges where the musket’s accuracy is unreliable, and it can easily dump 8 rounds into the user’s target while they’re foe is still reloading for a second shot.

In the end, a bullet is a bullet. If it connects and damages something you need to maintain a pulse, you’ll die. More bullets means that’s more likely for that to happen. While concepts like flatness and stopping power have a reality to them, they’re not good comparative tools to determining whether a gun can kill someone. And, quantified, numerical damage, is a fantasy.


This blog is supported through Patreon. If you enjoy our content, please consider becoming a Patron. Every contribution helps keep us online, and writing. If you already are a Patron, thank you, and come join us on Discord.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.