# Velocity of sound and bullets **URL:** \ **Category:** Factual Questions\ **Created:** [November 27, 2000, 7:55am UTC](https://boards.straightdope.com/t/velocity-of-sound-and-bullets/42842 "2000-11-27T07:55:34Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Ad\_Noctum](https://avatars.discourse-cdn.com/v4/letter/a/b19c9b/32.png) [@Ad\_Noctum](https://boards.straightdope.com/u/Ad_Noctum)\ **Post date:** [November 27, 2000, 7:55am UTC](https://boards.straightdope.com/t/velocity-of-sound-and-bullets/42842/1 "2000-11-27T07:55:34Z")
OK, say you are shooting a .270 cal 130Grain bullet at a target 300 feet away. Sound travels at around 1088FPS at 32F at Sea Level. a 130 Grain .270 Cal bullet travels with a muzzel velocity of 3060FPS and at 300 ft, the bullet slows down to 2776FPS. what I want to know is how much of a lag (seconds) will the sound have, following the impact of the bullet. Thank you Teeming Millions ---
**Author:** ![Badtz\_Maru](https://avatars.discourse-cdn.com/v4/letter/b/e36b37/32.png) [@Badtz\_Maru](https://boards.straightdope.com/u/Badtz_Maru)\ **Post date:** [November 27, 2000, 8:07am UTC](https://boards.straightdope.com/t/velocity-of-sound-and-bullets/42842/2 "2000-11-27T08:07:39Z")
You have all the info needed for the answer right there! It’s not even very complicated math! ---
**Author:** ![Ad\_Noctum](https://avatars.discourse-cdn.com/v4/letter/a/b19c9b/32.png) [@Ad\_Noctum](https://boards.straightdope.com/u/Ad_Noctum)\ **Post date:** [November 27, 2000, 8:15am UTC](https://boards.straightdope.com/t/velocity-of-sound-and-bullets/42842/3 "2000-11-27T08:15:09Z")
you forget, I’m a lazy-ass ---
**Author:** ![Badtz\_Maru](https://avatars.discourse-cdn.com/v4/letter/b/e36b37/32.png) [@Badtz\_Maru](https://boards.straightdope.com/u/Badtz_Maru)\ **Post date:** [November 27, 2000, 8:16am UTC](https://boards.straightdope.com/t/velocity-of-sound-and-bullets/42842/4 "2000-11-27T08:16:17Z")
Use a calculator! 8^) ---
**Author:** ![Badtz\_Maru](https://avatars.discourse-cdn.com/v4/letter/b/e36b37/32.png) [@Badtz\_Maru](https://boards.straightdope.com/u/Badtz_Maru)\ **Post date:** [November 27, 2000, 8:20am UTC](https://boards.straightdope.com/t/velocity-of-sound-and-bullets/42842/5 "2000-11-27T08:20:44Z")
Actually, looking back over the question, not all of the info is there since the bullet is decelerating. If it smoothly went from 3060 FPS to 2776 FPS over the 300 feet, you could just use the average of the two speeds, but the thing is the deceleration is not going to be even…but assuming it was…the bullet would take .1028 seconds to travel the 300 feet, the sound would take .2757 seconds, so there would be a .1729 second delay. ---
**Author:** ![Ad\_Noctum](https://avatars.discourse-cdn.com/v4/letter/a/b19c9b/32.png) [@Ad\_Noctum](https://boards.straightdope.com/u/Ad_Noctum)\ **Post date:** [November 27, 2000, 8:37am UTC](https://boards.straightdope.com/t/velocity-of-sound-and-bullets/42842/6 "2000-11-27T08:37:15Z")
thank you thank you thank you thank you!!! (not that this is an important question or anything, I was just kinda wondering and then didn;t want to take the time to figure it out…) ---
**Author:** ![Badtz\_Maru](https://avatars.discourse-cdn.com/v4/letter/b/e36b37/32.png) [@Badtz\_Maru](https://boards.straightdope.com/u/Badtz_Maru)\ **Post date:** [November 27, 2000, 8:43am UTC](https://boards.straightdope.com/t/velocity-of-sound-and-bullets/42842/7 "2000-11-27T08:43:11Z")
Here’s the math I used, in case you need to figure it out again with different figures. Average Velocity of Bullet: 3060 + 2776 / 2 (2918) Time for Bullet to Travel 300 Feet: 300 / 2918 Time for Sound to Travel 300 Feet: 300 / 1088