QUERY
Can you estimate how far a shooter is away if you have a mic recording close to the target and can measure a supersonic crack-thump?
9/10 VERIFIED
BIAS: CENTER
๐๏ธPolitics
1. ANSWER
Yes, you can estimate the shooter's distance using a microphone near the target by measuring the time delay (ฮt) between the supersonic crack (bullet's shock wave as it passes nearby) and the thump/bang (muzzle blast sound arriving later). The physics: bullet travels faster than sound (~800 m/s for rifle rounds vs. ~343-350 m/s sound speed), so crack arrives first; delay depends on distance (d) via approximate formula:
d โ ฮt ร (1/c - 1/v), where c = speed of sound, v = average bullet velocity.
Rough rules: 0.5s delay โ 300 yards; 1s โ 600 yards (FM 23-10 manual). Accuracy: ~10-20% error due to bullet drag, weather, mic position; validated in forensics (e.g., Trump rally: 217 ms โ ~135 m).123
2. EVIDENCE
- Forensic analysis (Trump rally, 2024): Podium mic near target recorded ~217 ms between crack (shock wave) and thump (muzzle blast). Using c=350 m/s, v=800 m/s (AR-15 .223 Rem, avg. 795 m/s over distance): d โ 0.217 ร (1/350 - 1/800) โ 135 m, matching rooftop shooter location. Robert C. Maher, Montana State Univ. prof., JAES paper (advance pub. Nov. 2025, analysis from Jul. 13, 2024).1
- Military "Crack-Thump" method: US Army FM 23-10: Time crack (bullet pass) to thump (muzzle sound); 1s โ 600 yards, 0.5s โ 300 yards for typical supersonic calibers (e.g., 5.56mm, v~2-3x sound speed). Assumes ~340 m/s sound, bullet drag; effective <500m before transonic effects. YouTube explainer (2026 crawl, cites manual).3
- Acoustics.org (Nov. 5, 2024): Maher confirms crack-then-bang in downrange mic; tiny ฮt yields ~130m in rally audio, verified by evidence. Same author as JAES.2
No conflicting info; peer-reviewed/academic/military sources consistent. Calculators exist (e.g., superfly.co.nz/ct.htm) for inputs like v, ฮt, c.4
3. CREDIBILITY
9/10. Strong: peer-reviewed forensics (JAES), military doctrine (FM 23-10), real-world validation (Trump rally matched physical evidence). Minor limits: needs known/estimated v, weather data; less precise >500m or subsonic ammo.
4. BIAS
CENTER. Sources: academic (Montana State Univ., Acoustical Society), US Army manual, neutral forensicsโno political slant.123
Yes, you can estimate the shooter's distance using a microphone near the target by measuring the time delay (ฮt) between the supersonic crack (bullet's shock wave as it passes nearby) and the thump/bang (muzzle blast sound arriving later). The physics: bullet travels faster than sound (~800 m/s for rifle rounds vs. ~343-350 m/s sound speed), so crack arrives first; delay depends on distance (d) via approximate formula:
d โ ฮt ร (1/c - 1/v), where c = speed of sound, v = average bullet velocity.
Rough rules: 0.5s delay โ 300 yards; 1s โ 600 yards (FM 23-10 manual). Accuracy: ~10-20% error due to bullet drag, weather, mic position; validated in forensics (e.g., Trump rally: 217 ms โ ~135 m).123
2. EVIDENCE
- Forensic analysis (Trump rally, 2024): Podium mic near target recorded ~217 ms between crack (shock wave) and thump (muzzle blast). Using c=350 m/s, v=800 m/s (AR-15 .223 Rem, avg. 795 m/s over distance): d โ 0.217 ร (1/350 - 1/800) โ 135 m, matching rooftop shooter location. Robert C. Maher, Montana State Univ. prof., JAES paper (advance pub. Nov. 2025, analysis from Jul. 13, 2024).1
- Military "Crack-Thump" method: US Army FM 23-10: Time crack (bullet pass) to thump (muzzle sound); 1s โ 600 yards, 0.5s โ 300 yards for typical supersonic calibers (e.g., 5.56mm, v~2-3x sound speed). Assumes ~340 m/s sound, bullet drag; effective <500m before transonic effects. YouTube explainer (2026 crawl, cites manual).3
- Acoustics.org (Nov. 5, 2024): Maher confirms crack-then-bang in downrange mic; tiny ฮt yields ~130m in rally audio, verified by evidence. Same author as JAES.2
No conflicting info; peer-reviewed/academic/military sources consistent. Calculators exist (e.g., superfly.co.nz/ct.htm) for inputs like v, ฮt, c.4
3. CREDIBILITY
9/10. Strong: peer-reviewed forensics (JAES), military doctrine (FM 23-10), real-world validation (Trump rally matched physical evidence). Minor limits: needs known/estimated v, weather data; less precise >500m or subsonic ammo.
4. BIAS
CENTER. Sources: academic (Montana State Univ., Acoustical Society), US Army manual, neutral forensicsโno political slant.123
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ANALYZED 4/9/2026, 8:42:58 PM โ POWERED BY AI