# The physics of firing a gun in mid-air

**URL:** <https://boards.straightdope.com/t/the-physics-of-firing-a-gun-in-mid-air/335572>\
**Category:** Factual Questions\
**Created:** [December 14, 2005, 1:10pm UTC](https://boards.straightdope.com/t/the-physics-of-firing-a-gun-in-mid-air/335572 "2005-12-14T13:10:02Z")\
**Posts on this page:** 1\
**Page:** 2

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**Author:** ![matt](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@matt](https://boards.straightdope.com/u/matt)\
**Post date:** [December 15, 2005, 5:35pm UTC](https://boards.straightdope.com/t/the-physics-of-firing-a-gun-in-mid-air/335572/21 "2005-12-15T17:35:31Z")

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> [@mittu](#):
>
> If I may just bring this thread back onto the original topic (yes the game was BF2)
> 
> A friend just pointed out that some amount of recoil would result due to the rocket like effect of the gas escaping the end of the muzzle, does anybody have any ideas on how to calculate the magnitude of this effect for the weapon in question?

An efficient sound supressor captures much of the escaping gas and robs it of its energy, so the recoil reduction from using a suppressor should be an indicator.

[This site](http://guns.connect.fi/gow/highpow.html) claims that the escaping gas is responsible for about half the recoil. (About a quarter down the page: “Sound Level and Recoil”.) It also claims that a suppressor reduces recoil energy by 20-30%.

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