Chrono/Load Issue?

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unwashed

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So, went to the range today to test some .45 loads and set up my chrony about 12 ft away. But before I shot the .45 I shot my 9mm since I had more rounds, to make sure everything is working, lol. It was very sunny which my chrono doesn't like but I believe most don't. I installed the diffusers. My first shot didn't register, On my second, the left front rod and diffuser goes flying off, bent and on the ground. The sensors are intact. Thinking I shot it, retrieve it and straighten it out the best I could, just so it covers the sensor. Shot again and got a wrong reading 25xx. Second shot the same rod goes flying and bent, now I'm saying no way I misaimed twice but it happens. I repeat the fix and move the chrono back for a total of about 18 ft and the next shot the rear left rod and diffuser goes flying and bent. There's no way I misaimed 3 times. So I quit for further investigation, :) Btw, I did get 1 reading that seem close, 650 fps.

My thought is un-burnt powder and/or gases traveling behind caused the damage. Any thoughts would be appreciated.
The load I was using is 9mm Federal cases, win spp, 5.1 grs CFE-P, 124gr XTP seated at 1.060. Loaded
20210517_120024.jpg 20210517_120017.jpg
 
It's not the gases. Gas pressure does not bend steel like that. You're hitting it with bullets.

Check your gun to see if the sights have moved.
 
Are you saying you didn't see any strike marks the bullet could have made? Were you loading subs? :thumbdown:
 
unwashed said:
So, went to the range today to test some .45 loads and set up my chrony about 12 ft away. But before I shot the .45 I shot my 9mm since I had more rounds, to make sure everything is working, lol. It was very sunny which my chrono doesn't like but I believe most don't. I installed the diffusers. My first shot didn't register, On my second, the left front rod and diffuser goes flying off, bent and on the ground. The sensors are intact. Thinking I shot it, retrieve it and straighten it out the best I could, just so it covers the sensor. Shot again and got a wrong reading 25xx. Second shot the same rod goes flying and bent, now I'm saying no way I misaimed twice but it happens. I repeat the fix and move the chrono back for a total of about 18 ft and the next shot the rear left rod and diffuser goes flying and bent. There's no way I misaimed 3 times. So I quit for further investigation, :) Btw, I did get 1 reading that seem close, 650 fps.

My thought is un-burnt powder and/or gases traveling behind caused the damage. Any thoughts would be appreciated.
The load I was using is 9mm Federal cases, win spp, 5.1 grs CFE-P, 124gr XTP seated at 1.060. Loaded
View attachment 999046 View attachment 999047
Click to expand...
that’s a cool looking range! But they allow you at the shoot table with people down range?
 
I took a closer look but tool marks on them from straighten them makes is difficult. The front left was the very first shot so I just assumed it was me and straighten it and moved on. By the second and third time I reconsidered. The span from center to the left at the joint is 4"-5", sights could be this far off at 12 ft and considering I never had a problem before. If it's my crappy shot I'll have to work on that but still hard for me to believe it was me.

Oh, no subs.
 
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That's assuredly caused by a heavy chunk of lead traveling at high speed. I know because I've done it (loose rifle optic in my case).
 
Thomasss said:
There are two types of people with chronies; people with new un-opened chrony boxes and people with shot up chronies. Welcome to experienced chrony users.
Click to expand...
That my second chrono and this one has a .223 through it but in this case, it's me and questioning my skill 3 times or gremlins. I'm going with gremlins :rofl:
 
Definitely a gremlin - the one behind the gun!;) Pulling left...bet you're a righty. Stand closer to your chrono and you'll be less likely to hit it. Handgun muzzle to chrono should be 6-9 ft.
 
The gasses exiting the barrel can cause the erroneous readings. Move the chronograph a bit farther away from the gun.

The bent diffuser rods are definitely from bullet strikes.

Get some wood dowels for replacements. If hit again, they will break and not cause as much impact to the chronograph. Keep some spares with you when you go to the range. Aim more carefully.

FYI, I've had two chronographs expire from "lead poisoning". They do not respond well to 45 ACP or 204 Ruger.
 
Bad news is, that's definitely a bullet strike.
It really doesn't take much movement to strike one of those rods when shooting through a chrony. Might have been anticipating what the reading would be and pulled it slightly.
I know it's happened to me and my shooting buddies before.
 
I've hit a shade wire before, I said dad it needs to be rotated a little bit. He was like send it. 223 cuts it clean in 2. He was pissed but I told him.
 
AJC1 said:
I've hit a shade wire before, I said dad it needs to be rotated a little bit. He was like send it. 223 cuts it clean in 2. He was pissed but I told him.
Click to expand...
Old people never listen to younger people!

SEND IT!
 
Wooden dowels and few spares will make a big difference. Also, maybe a target a couple feet behind the chrono just so you know where the rounds are actually going. Once you know everything is right, then remove the close target. Not that I know any of this from experience, but I heard it from a guy that does. Don’t feel bad, I have nicked one before too.
 
Thanks guys, will go and try again and be more attentive this time. I was really hoping it was the same gremlins that steal my cases at the indoor range, :)
 
I always find it more difficult to setup for pistol than rifle. With rifle you most use some kind of rest, were you normally don't for pistol. When I setup for pistol I setup some kind of rest for the barrel to have a reference on where to align up with. And I only setup 1 target. With multiple targets your moving around. I try to place the bullet at least 4-5" above the crony.

You can mount your crony upside down and not use the shades. I found out on mine that I drop reading long before I get to the support rods.
 
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