Good work. As an experienced civilian and military rifleman having owned and used these platforms for 2+ decades, in posts many days ago, I suggested the likely variation range would be between 2900 to 3100 fps with the most common ammo in a 16 to 18 inch barrel AR15. I think your tests have verified my thoughts. Thank you for the testing.
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Is there a permanent link somewhere on this website to this? I looked for it for a long time thru threads. Seems it should be linked or tabbed somewhere.
@cmartenson
Quick note on snick-boom times of 123 vs 45678 from podium mic as being diagnostic of a second shooter.
A 1 or 2 percent difference in time would mean a 1 or 2 percent difference in distance only if the muzzle velocities were identical.
If there was also a few percent difference in muzzle velocities, but in our calculations we assume equal velocities then we can be off by a lot, in either direction depending on which bullets were slower and which were faster.
I think TDOA analysis of the reports are likely to be more accurate regarding location assuming we have good enough data - particularly non moving microphones of known location.
But if the snick-boom times of 123 vs 45678 are significantly different on the podium mic recording - this is pretty strong evidence of a second shooter [edit - or maybe not, see below] : you just can’t say whether the second shooter was nearer or farther without knowing relative muzzle velocities.
The snick-boom time is also affected by accuracy of the shot. If the shot misses the microphone by an extra 1.15 foot, this will subtract about 1 msec from the snick-boom time (assuming speed of sound of 1150 feet per second).
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Excellent point. So, theoretically:
Professional 280 meters away uses 5.56 traveling 3300 fps. Shots are closer proximity to Trump’s mic.
Crooks 140 meters away uses .223 traveling 2800 fps. Shots are 10 meters farther from Trumps mic.
The boom-snick report for these will be different, but how?
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It gets worse. For the shot that hit Corey, the time for the sound of the report to reach the mic is unchanged. But the time for the snick to reach the mic instead of distance of shooter to mic divided by bullet speed, it is distance of shooter to Corey divided by bullet speed plus distance from Corey to mic divided by speed of sound. That could make a significantly shorter snick-boom time.
Hi everyone, this is pseudo stereo. Left channel is Trump’s mic, right channel is western footage.
https://drive.google.com/drive/folders/1WTIh6bS5n4rRuG1pYIgFG1vaMyyZ1657?usp=sharing_eip&ts=66bbca56
(Note: this is all hypothetical, not real data)
That’s a good question, quite a big difference:
I’m going to just use feet
| Crooks | Professional | |
|---|---|---|
| feet | 459 | 919 |
| Speed Round | 2800 | 3300 |
| Speed Sound | 1150 | 1150 |
| Snick-boom | 0.235 | 0.520 |
But suppose the difference in distance is not so great, say a 2nd floor window from the building just behind Crooks. Add an extra 53 feet. And let’s reverse your speeds, so the Professional’s muzzle velocity is actually slower than Crooks’ gun. And ignore the “missed the microphone by” factor. You can engineer almost identical snick-boom times.
| Crooks | Professional | |
|---|---|---|
| feet | 459 | 512 |
| Speed Round | 3300 | 2800 |
| Speed Sound | 1150 | 1150 |
| Snick-boom | 0.260 | 0.262 |
Or suppose one shooter, second shot hits Corey.
I’m not sure how far Corey was to the microphone; I’m guessing 30 feet.
| Missed | Hit Corey | |
|---|---|---|
| feet | 459 | 459 |
| Speed Round | 2800 | 2800 |
| Speed Sound | 1150 | 1150 |
| Corey to mic dist | 30 | 30 |
| Shooter to Corey | 429 | 429 |
| Round to Corey | 0.153 | |
| Sound Corey to mic | 0.026 | |
| Gun fire to snick | 0.164 | 0.179 |
| Sound gun to mic | 0.399 | 0.399 |
| Snick-boom | 0.235 | 0.220 |
Bottom line; if we look at the shot that struck Corey, and if that shot still delivered a sonic boom to the mic (it may not have), this would lead to a shorter snick-boom time on the order of one millisecond for each 2 feet Corey was in distance to the microphone.
Do we have a group consensus on snick-boom times for each of the shots? And do we know which one hit Corey?
I looked up the temperature in Butler for that day and found “93 deg F”. Then I used an altitude of 408m and https://e6bx.com/speed-of-sound/ to compute the speed of sound as 351.18 m/s
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You might want to check out this post. It’s the most detailed post on the subject I’ve run across.
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Wow, @vt1, that video is really amazing! Thanks for sharing, and thanks for doing the supersonic cone illustration. I did some online searching yesterday to see if I could find how close you had to be to the path of a bullet to hear its sonic crack, but I was not not successful at finding a clear answer, or a formula.
I recently added the police cruiser that pulled up to the front door of the AGR building to my TDOA analysis. I expected it to provide some valuable insight to the scenario since I knew what its exact location was, and it did not move, whereas TMX and DJStew were both definitely moving. Unfortunately, instead of simply providing answers, the cruiser added more questions. On a positive note, I am seeing amazing consistency for the first 8 shots. The cluster is confined to less than 2 meters. However, shots 9 and 10 are now providing three potential solutions, and the locations implied by the Cruiser put the counter-snipers in the line-of-sight that would be occluded by the tree, so that seems unlikely. The attached PDF shows “podium-centric” plots for the first 10 slides and “TMX-centric” plots for the second set of 10. With “centric” meaning that the TDOA plots are sure to include “podium” in the first set and “TMX” in the second.
So, now I’m confused. I’ve tried some “what if” scenarios, like what if the sounds being heard by the Stewert camera were sonic cracks instead of reports, but nothing I’ve tried has yielded any improvement/clarity to the TDOA hyperbolas. So, suggestions from you or anyone else are appreciated at this point!
My 4.4MB PDF file was apparently too large for me to upload this forum. So, here is a link to it.
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| Description | Time | Diff |
|---|---|---|
| Snick 1 | 0.000 | |
| Report 1 | 0.221 | 0.221 |
| Snick 2 | 0.858 | |
| Report 2 | 1.075 | 0.217 |
| Snick 3 | 1.536 | |
| Report 3 | 1.748 | 0.212 |
| Snick 4 | 4.319 | |
| Report 4 | 4.531 | 0.212 |
| Snick 5 | 4.575 | |
| Report 5 | 4.787 | 0.212 |
| Snick 7 | 4.939 | |
| Snick 8 | 5.088 | |
| Report 8 | 5.306 | 0.218 |
Snick 6 is missing because the bullet hit Corey.
Reports 6 & 7 are not heard because audio AGC was overcome by snicks 7 & 8.
I estimate that reports 6 & 7 came in at 4.971 and 5.154 based upon the snick/report deltas of the other shots.
I’m reaching a solution for the time of the sonic slick considering the bullet deaccelerating. Still validating the formulation. I will study your plots. I’m thinking if you had more sources closer to Trump would improve the 9 and 10 shoot accuracy, like the RSBN broadcast source.
Sorry if I missed it, but did you take a look at this possible problem? I don’t know if it’s correct, but it was high-quality. Now We Have MORE Questions (Pointing To LIHOP) - #450 by sonjax6
Chris thinks it might be shot #6 as it has a Boom without a Snick.
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Greg I think that the accuracy has a lot to do if the dipoles receivers form a triangle and the source is inside the triangle. Therefore, the accuracy is high for Crooks position but not for Shots 9 and 10. There are other 2 receivers near the podium you can use.
Here is the Middle Bleacher POV, I triangulated the position from the flags and far objects.
Video footage moments before Donald Trump Rally assassination attempt…mp4 (dropbox.com)
I can hear 4 shots, IDK if there is more footage.
586744.37 m E; 4523392.48 m N; elevation 1343ft (409.34m) + height 13ft (3.96m)
Here is the RSBN:
The video has a small footage in the top right corner from another POV. IDK if the sound receiver is in that location. Maybe by the sonicboom and report time diference we can confirm the location.
586682.44 m E ; 4523381.43 m N; elevation 1344ft (409.65m) + height 10ft (3.05m)
Which helps us narrow down the possible shooting locations…Besides providing cover from being seen from the parking lot, it’s entirely out of sight of both SS sniper teams while still having a clear shot at Trump. We’ll be working to resolve the audio data and echoes against this and one other possibility.
The actual enemy sniper(s) would most likely be concealed and have viable escape plan. The Pasty on the roof and exposed would be the distraction/ cover story.
Keep up Great work,
Regards,
k
forgot the quotes-first paragraph.
sorry
-k
Chris, did you finally get the make/model of the Trump’s mic and the gating characteristics of the mic and/or gating characteristics of the board the mic was feeding?
The somewhat slow sequence of shots 1-3 vrs. the rapid fire of shots 4-8 and gate recovery time could affect the audio spectrum and could account for the difference between the shots.
From a theory point of view, I would tend to believe a second shooter would have been the one who radicalized Crooks, and would have been onsite to finish the job in case Crooks failed, or to even take Crooks out if it looked like he’d be taken alive. (Dead men tell no tales.)
I also wonder if this could have been a dry run (with a possibility of “success”) to analyzes weaknesses and strengths of a future attempt.
Greg, are you aware that the police cruiser video contains three audio streams (front, passenger cabin, rear)?
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But we know he PURCHASED the rounds used so personal plinking loads are not relevant.
Your numbers on the purchased rounds agrees exactly with what I have already posted.
But you didn’t test any 77 gr rounds. Especially OTM 77 gr rounds which are the type used for distance shooting.
How about those?
The ones you did test just confirm my analysis that IF those were the rounds used, then THERE WAS A 2nd SHOOTER for sure.