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Reloading Equipment WTS: 1x Fired Hornady Factory 6.5 CM Brass
- Buy - Sell - Trade
- 0 Replies
FOR SALE:
PM me first to avoid scammers. I will not PM you.
Accepting PayPal FF, Zelle only.
Will ship out same day or first thing next biz day when possible.
- 600 pieces of 1x Fired Hornady Factory 6.5 Creedmoor Brass.
- Bagged in 200 count ziploc bags. Count verified twice
- All 140 ELD-Match Factory Ammo.
- Shot from a Proof Comp Contour 26" SS barrel.
- Walnut Media tumbled. NOT DE-CAPPED!
- Will not ship in OEM packaging.
- Price: $110 per 200 count bag or $300 for all 600 as 1 lot sold in 1 transaction.
PM me first to avoid scammers. I will not PM you.
Accepting PayPal FF, Zelle only.
Will ship out same day or first thing next biz day when possible.
Americans
- The Bear Pit
- 25 Replies
And, as a native born Englishman who chose America as his country rather than becoming a citizen by accident of birth, I still find this funny
Precision Rifle Gear Chronograph Testing: Gun Mount vs. Static
- By Varminterror
- The Armory
- 2 Replies
I have a LOT of data out there, and a lot more coming, which illustrates differentiation in the readings between some of these units.
For example - without intending to distract from the purpose of this specific thread about the mounted vs. static influence on velocity reading - here are a few comparisons where I shot a bunch of rounds across 6 chronographs at a time to be able to tell how each brand read compared to the others, and how closely together the 2 units of each brand measured to one another.
This was a preliminary test using rot-gut, bulk rimfire ammo, so the ES of the 100 round string was ~245fps... But still some valid observations could be made:
The Heatmap here gives a visible representation of which units typically read faster or slower than the others - the Athlons, in this test, measured slower in 89 of the 100 shots than the other 2 brands. The LabRadars measured faster than the other 2 brands in 90 of the 100 shots, with the Garmins falling in the middle of the LX's and the Athlons for 85 of the 100 rounds. Reds are the slowest readings for each shot, greens are the fastest readings for each shot.
For this string, the 2 Garmins averaged only 0.544fps difference between the two units, with only 1.9fps as the maximum difference in the two measurements. The LabRadar LX's measured ~50% more difference, on average, between the two LX's, and the max difference between the two was twice as wide as the Garmins. In principle, the Garmin achieved the stated specification of precision of +/-0.1%, assuming the true measure is between the two units, whereas the LabRadar LX demonstrated wider than stated precision. The Athlons here had an average of 1.068fps difference between the two units, with the worst difference between the two for any single shot being 6.5fps.
In a snippet of this data, re-ordered according to increasing velocity to make the offset more easily visible, we could see the Garmins and LX's kind of hang closer together with smaller variability, while the Athlons kind of float around farther below the other two:
Interestingly, the Average velocities from all 6 units were only 2.3fps apart - certainly close enough to one another to claim all of them read the same Average Velocity for all practical purposes.
Shooting this same experiment with 50rnds of centerfire:
The Athlons shifted from the slowest readings in the first test to the fastest, and the LX's moved to the slowest. I missed several shots with one or both of the LabRadars, but when all 6 read, the LabRadars exhibited the slowest reading in 36 of the 39 shots, whereas the Athlons read the fastest readings for 51 of the 51 shots they read. So there does seem to be a little "float" in the offset
The averages did spread out between the units in this experiment, with the Garmins again agreeing VERY tightly together - within 0.1fps, the LX's agreeing relatively tightly, only 2.2fps spread, and the Athlons agreeing tightly together at only 0.8fps spread, but the Athlons did read ~8-13fps faster than the other 4 units of the other 2 brands. (Note, I was relatively stoked that my ammo held single digit SD's for 50rnds, especially since I'm putting my data out there for public consumption).
The Garmins again offered the most consistent readings from one Athlon to the next, with only 0.95fps average difference between the two, and never more than 2.8fps as the maximum difference between the two Garmins (again, theoretically within the specified +/-0.1% precision). The LX's were more than twice as far spread, on average, at 2.56fps average difference in reading, and the maximum difference between the two LX's was 15.2fps - far outside of the specified precision. The Athlons averaged 6.48fps average difference between the two units, with a maximum difference measured of 19.4fps.
Visualizing this again by plotting the readings for each shot in increasing velocity order, we again see the offset of the Athlon readings floating higher above the relatively tightly clustered LX and Garmin trends, and displaying greater variability throughout the string.
Repeating this for another 99 round rimfire string, using this time CCI SV, the 2 Athlons were again higher for almost all shots than the LX's or Garmins (98 out of 99), and again showed a bit more variability, although notably less than the above strings.
The Average for the 2 Garmins and 1 of the LX's were exactly the same at 1082.9, with the 2nd LX only differing by 0.6fps, while the 2 Athlons agreed within 0.5fps of one another, but ~4fps faster than the other 4 units. 4fps error won't miss targets.
Looking at these results, it's easy to get itchy about the variability of the Athlon data, but, I also think a shooter has to calibrate expectations a little - the average velocity displayed by all of these is still very close together, and in almost all cases, wouldn't represent more than an inch of realized elevation error at 1k.
