Re: Thoughts/Opinions on Chronographs
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fnbrowning</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JimGnitecki</div><div class="ubbcode-body">Anyone seriously considering, or defending, the Chrony might find this true, first-hand story interesting.
Today, I was at the range testing my first 338 Lapua hand loads. I have no chronograph, so was just shooting ladder test groups and looking at the group sizes and vertical dispersion.
A new friend offered to chronograph one of my loads for me. He had brought a brand new Chrony to the range today.
Pay attention to this next part: The load is:
Ptimer: Federal Large Rifle Mangnum
Case: Lapua
Bullet: Sierra 300g Matchking
Powder: 87g of Retumbo
Just prior to the chronograph test, I had fired a 4 shot group, at 250 YARDS, that was only 3/4 " vertically by around 2" horizontally (gusty wind, 45 degrees, I was wearing GLOVES it was so darn cold!). So, we are talking 0.3 MOA vertical by 0.8 MOA horizontal.
The Chrony delivered the following results:
1st shot: 3253 fps
2nd shot: 3328
3rd shot: 3360
4th shot: 3409
5th shot: 3404
Average: 3351
Extreme spread: 156.7
Std Deviation: 64
Now ask yourself:
1. Can 87 grains of Retumbo actually push a 300g .338 caliber Matchking at 3351 fps? Could ANY 300g 338 Lapua load deliver 3351 fps without blowing up the case and rifle both? The loading books all suggest this load should deliver somewhere in the 2400 to 2500 fps range.
2. Is a group with 0.3 vertical MOA compatible with SD = 64 and extreme spread of 156.7?
My new friend was as "skeptical" as I was, and tested a 308 hand load, in his rifle, that he KNOWS does about 2550 out of the barrel. The Chrony said it did 3410.
So, did I learn anything of value about my load by using the Chrony? Did I learn anything of value about the CHRONY?
Jim G
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Oh for cripes sake, back off the Chrony so the muzzle blast isn't being measured. The alert reader can't be seriously considering, or defending this tale, unsupported by other evidence, purporting that the Chrony product or design is a complete failure.
No where on any gun board, will you find evidence of <span style="font-style: italic">systemic</span> failures in the Chrony line of chronographs. I concede that the manufacturer might have shipped a defective unit, IF you admit that no manufacturer is perfect. I don't know what customer service the other companies give, when I needed service on my Shooting Chrony, they were helpful. I would buy their products again.
Other brands may look better, have more features and have more prestige.
But the Chrony will work if you give it a chance. It is, after all, the Chevy of the chronograph world.
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There were 4 witnesses. The Chrony was 15 feet from the firing line. The problem was encoutnered firing first 338 Lapua from my TRG and then .308 from the Chrony owner's semiauto. I just reported what actually happened.
I did like the remote he had atatched to the Chrony. MUCH nicer to use than trying to read a display on a unit 15 feet downrange.
Jim G
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fnbrowning</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JimGnitecki</div><div class="ubbcode-body">Anyone seriously considering, or defending, the Chrony might find this true, first-hand story interesting.
Today, I was at the range testing my first 338 Lapua hand loads. I have no chronograph, so was just shooting ladder test groups and looking at the group sizes and vertical dispersion.
A new friend offered to chronograph one of my loads for me. He had brought a brand new Chrony to the range today.
Pay attention to this next part: The load is:
Ptimer: Federal Large Rifle Mangnum
Case: Lapua
Bullet: Sierra 300g Matchking
Powder: 87g of Retumbo
Just prior to the chronograph test, I had fired a 4 shot group, at 250 YARDS, that was only 3/4 " vertically by around 2" horizontally (gusty wind, 45 degrees, I was wearing GLOVES it was so darn cold!). So, we are talking 0.3 MOA vertical by 0.8 MOA horizontal.
The Chrony delivered the following results:
1st shot: 3253 fps
2nd shot: 3328
3rd shot: 3360
4th shot: 3409
5th shot: 3404
Average: 3351
Extreme spread: 156.7
Std Deviation: 64
Now ask yourself:
1. Can 87 grains of Retumbo actually push a 300g .338 caliber Matchking at 3351 fps? Could ANY 300g 338 Lapua load deliver 3351 fps without blowing up the case and rifle both? The loading books all suggest this load should deliver somewhere in the 2400 to 2500 fps range.
2. Is a group with 0.3 vertical MOA compatible with SD = 64 and extreme spread of 156.7?
My new friend was as "skeptical" as I was, and tested a 308 hand load, in his rifle, that he KNOWS does about 2550 out of the barrel. The Chrony said it did 3410.
So, did I learn anything of value about my load by using the Chrony? Did I learn anything of value about the CHRONY?
Jim G
</div></div>
Oh for cripes sake, back off the Chrony so the muzzle blast isn't being measured. The alert reader can't be seriously considering, or defending this tale, unsupported by other evidence, purporting that the Chrony product or design is a complete failure.
No where on any gun board, will you find evidence of <span style="font-style: italic">systemic</span> failures in the Chrony line of chronographs. I concede that the manufacturer might have shipped a defective unit, IF you admit that no manufacturer is perfect. I don't know what customer service the other companies give, when I needed service on my Shooting Chrony, they were helpful. I would buy their products again.
Other brands may look better, have more features and have more prestige.
But the Chrony will work if you give it a chance. It is, after all, the Chevy of the chronograph world.
</div></div>
There were 4 witnesses. The Chrony was 15 feet from the firing line. The problem was encoutnered firing first 338 Lapua from my TRG and then .308 from the Chrony owner's semiauto. I just reported what actually happened.
I did like the remote he had atatched to the Chrony. MUCH nicer to use than trying to read a display on a unit 15 feet downrange.
Jim G