9mm chrony/velocity issues

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hardheart

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90 degree day, sunny
Shooting chrony beta
CZ75B (4.7")
Berry's 124 gr HBRN
Mixed brass
Win Spp
1.135" oal

First, Win white box NATO 124 gr, two shots:
1466, 1471

5 shot results:
6.3 gr power pistol
Avg 1236
SD 23.9
ES 73

5.5 gr longshot
Avg 1454
SD 5.7
ES 18

Short leade on the CZ precludes longer oal.
 
If the question is, do these velocities sound correct? The answer is no. Getting nearly 1500 fps from NATO 124 with a 4.7" barrel is highly unlikely. Two shots is not a very large sample, however. The reload velocities could be correct. I would shoot some more of the white box and see if you get velocities in the 1200 fps range, which is what I would expect.

EDIT: Just to note, optical sensor chronographs are prone to errors, especially when the light isn't right. I have gotten some crazy readings before, then had a long string of seemingly accurate readings in the same session. Since I am a meticulous reloader, I always just assume that any reading that is way off in either direction is just a bad reading.
 
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f the question is, do these velocities sound correct? The answer is no
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Agree
1450+ fps with a 124gr in 9mm in a pistol is way high. I would expect something around 1200 for the Longshot load at that OAL.
 
hardheart said:
1.135" oal
Berry's 124 gr HBRN
Short leade on the CZ precludes longer oal.
Click to expand...

You've chosen a very good OAL for that bullet weight, it should deliver excellent results. But if you'll check I believe you'll find that all the Berry RN can be loaded out past the SAAMI max in CZ chambers. Not trying to create trouble, only to point out that what ever measurement method or tool that gave you that answer is in error.
 
Must be a chrono error because all tests of Win 124 gr white box shows 1140-1150 fps maximum. Might be too close to the skyscreens and it's reading the muzzle blast? A 1200 fps velocity is about tops for 124 gr. 9MM factory or reloads.
 
rfwobbly said:
You've chosen a very good OAL for that bullet weight, it should deliver excellent results. But if you'll check I believe you'll find that all the Berry RN can be loaded out past the SAAMI max in CZ chambers. Not trying to create trouble, only to point out that what ever measurement method or tool that gave you that answer is in error.
Click to expand...
I did a few plunk/push tests and load to keep the round off the lands. Also, Zero JHP can't go past 1.05 in mine as well.
 
rg1 said:
Must be a chrono error because all tests of Win 124 gr white box shows 1140-1150 fps maximum. Might be too close to the skyscreens and it's reading the muzzle blast? A 1200 fps velocity is about tops for 124 gr. 9MM factory or reloads.
Click to expand...
I was at about ten feet, maybe I stepped closer on loading a mag. But I'm also thinking it may have been the bright sunlight? The manual mentions it in troubleshooting errors. No cloud cover to speak of that day, and the shadow from the screens was cast to the side & not over the sensors. I'd also think the shot to shot variance wouldn't be so low if it was the ejecta causing issues? I've yet to have good consistency with PP, even with readings that seemed correct.
 
hardheart said:
I did a few plunk/push tests and load to keep the round off the lands. Also, Zero JHP can't go past 1.05 in mine as well.
Click to expand...

Your Zero 124gr JHP is in line with my Max OAL for the same bullet, but I have never known Berry RN to not have a Max OAL out past the SAAMI max OAL for 9x19. Don't change your OAL that you're using, because you'll get great results with 1.135". But for your own knowledge you might want to re-test that figure.

PM sent with explanation.
 
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