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+--- Thread: 123gr ELD Match BC Discrepancy (/showthread.php?tid=18829)
123gr ELD Match BC Discrepancy - SlappyAbbot - 04-23-2019
I just noticed that my Kindle copy of Hornady 10th Edition lists G1: 0.461 and the G7: 0.233. However, my box of Hornady Black lists G1: 0.506 and G7: 0.255. I only spent a few minutes searching for a reason behind this discrepancy, but did not find anything. So sorry if this is old news.
123gr ELD Match BC Discrepancy - NugginFutz - 04-23-2019
I can’t speak to the 10th edition, but I do know that I was shooting this weekend out to 1000 yards using .506 G1 and I actually had to adjust my mv upward to account for the drop errors. (My hits were a couple tenths of a mil off at 1000 yards). I should have been using the .255 for those distances, but the fact remains that a .461 would have been off by a serious margin.
ETA:
Checking my own sources, Box of black matches your #'s. Hornady's 4DOF app for the smart phone agrees with the boxes.
What I find interesting is that your kindle's #'s do not align with any of the Hornady bullets listed on their website for .264 / 6.5 mm.
I would seriously consider forwarding a request for correction to Hornady and send a screen shot.
p.s.
Welcome to the board!
123gr ELD Match BC Discrepancy - SlappyAbbot - 04-23-2019
Thank you. I figured I might send them an email, but wanted to confirm this was not a known issue.
123gr ELD Match BC Discrepancy - Bayouhunter1960 - 04-23-2019
May not be the answer to the discrepancy page 100 in the 10th edition
“Many of our ELD-X®and ELD®Match offerings were developed just in time for this 10thEdition publication. Our ballisticians continue to work on the data for ELD-X®and ELD®Match bullets, as well as our BTHP Match™bullets (currently published with 200 yard BCs) so we can publish BCs measured at varying distances on our website (Hornady.com/BC).
123gr ELD Match BC Discrepancy - SlappyAbbot - 04-23-2019
That might help explain it, thanks. I guess I'll just have to rely on box/website data.
123gr ELD Match BC Discrepancy - NugginFutz - 04-23-2019
Bayouhunter1960 Wrote:May not be the answer to the discrepancy page 100 in the 10th edition
Many of our ELD-X®and ELD®Match offerings were developed just in time for this 10thEdition publication. Our ballisticians continue to work on the data for ELD-X®and ELD®Match bullets, as well as our BTHP Matchbullets (currently published with 200 yard BCs) so we can publish BCs measured at varying distances on our website (Hornady.com/BC).
That being the case, why publish obvious erroneous data? A footnote would have sufficed, or just omit the data altogether, saving it for the next edition. Instead, they went with the "any data is better than no data" approach.
I wish they would show a little more concern over the accuracy of their information. What happens if this attitude crosses over into the load data section?
123gr ELD Match BC Discrepancy - Bayouhunter1960 - 04-23-2019
Traditionally, the industry standard for measuring BCs has been at 200 yards. A limited number of bullets are published with 400 to 600 yard BCs. Our new ELD-X®and ELD®Match bullets are published with 800 yard BCs measured with Doppler radar. It is important to note that as you calculate BCs at a further distance, the BC will go down slightly in value.
Many of our ELD-X®and ELD®Match offerings were developed just in time for this 10th Edition publication. Our ballisticians continue to work on the data for ELD-X®and ELD®Match bullets, as well as our BTHP Matchbullets (currently published with 200 yard BCs) so we can publish BCs measured at varying distances on our website (Hornady.com/BC).
The data on our website includes 200 yard BCs which help with bullet to bullet comparisons, as well as 500, 600, even 1,000+ yards which offer more value for the long distance shooter. We will continually build our library of data and hope you find it useful in planning your shooting ex
123gr ELD Match BC Discrepancy - Bayouhunter1960 - 04-23-2019
I’m not sure they are publishing erroneous data but I copied the rest of their explanation on differing BC’s for the same bullet, I wasn’t aware BC changes with range.
Their 10th edition lists the .264 123gr ELD Match SD: 252. G1 BC .461. G7 BC .233 MV range 1600-3300fps.
123gr ELD Match BC Discrepancy - centerfire - 04-23-2019
BC changes with velocity.
123gr ELD Match BC Discrepancy - SlappyAbbot - 04-24-2019
Compared some of the other ELD Match weights tonight (10th Edition vs website) and they are all similarly different. I guess that is not too surprising. However, the 143gr ELD-X is the same.
EDIT: I just sent them a message about it through their website to see if they have anything interesting to say.
123gr ELD Match BC Discrepancy - seven6twomm - 04-24-2019
To date Ive gotten the best BC data and bullet dimensions from Litz books or the Applied Ballistics app. If I get serious about shooting a bullet Ill pay the $3 and buy the Custom Drag Model from them which is a ballistic coefficient based on velocity decay through the transonic boundary verified by live fire.
123gr ELD Match BC Discrepancy - SlappyAbbot - 04-24-2019
NugginFutz Wrote:I can’t speak to the 10th edition, but I do know that I was shooting this weekend out to 1000 yards using .506 G1 and I actually had to adjust my mv upward to account for the drop errors. (My hits were a couple tenths of a mil off at 1000 yards). I should have been using the .255 for those distances, but the fact remains that a .461 would have been off by a serious margin.
I was playing around with the 4DOF Calculator last night and it looks like the Axial Form Factor setting might help with this. I had no idea what that was, so was reading about it on their Instructions page and it made me think of this post.
https://www.hornady.com/team-hornady/ballistic-calculators/4dof-ballistic-calculator/instructions
123gr ELD Match BC Discrepancy - SlappyAbbot - 04-24-2019
seven6twomm Wrote:To date I’ve gotten the best BC data and bullet dimensions from Litz’ books or the Applied Ballistics app. If I get serious about shooting a bullet I’ll pay the $3 and buy the Custom Drag Model from them which is a ballistic coefficient based on velocity decay through the transonic boundary verified by live fire.
Thanks for your input, I'll look into that. Sounds similar to what Hornady is advertising in their 4DOF app.
123gr ELD Match BC Discrepancy - seven6twomm - 04-25-2019
I never ran out and bought all the Applied Ballistics books right away but the app has been indispensable for me both as a shooting solution calculator and also a simulator to see what a bullet might do if it's going "x" velocity. The Custom Drag Models smartened things right up for me at distance, instead of being 8" low and 10" right at 700m, or missing at 1400m that shot is much, much closer to point of aim at all ranges. And it's cheap! $30 for the app...
123gr ELD Match BC Discrepancy - newb - 04-25-2019
Not sure if this will help for real world results vs stated info, but I would use the lower stated BC and here's why.....
I recall others a few years back saying AMAX needed to use lower BC for drop calc so I used that for the base BC which was said to use 0.42.
The trajectory didn't line up and I did do proper scope center to bore measurement. There could have been an error on my part somewhere, but I didn't look into it and just used the real world results as calc values to me are a starting point to get close and then map actual real world data, re-plot from there.
22" barrel. AMAX chrono'd pretty close around 2510 fps and my origial cal value I put 2500 before I had chrono data. 100 yd zero.
300 yds called for 4.82 MOA, I was 7 MOA. 500 yds called for 12.73 MOA (mine is 1/4 MOA increments) and 12.75 did perfect. This was the furthest I used AMAX for, I don't recall if 750 yds or not so I'll just say not.
Finally ran out of my AMAX stockpile and used the ELD last week or week before and don't recall that fps off the top of my head, but I think the ones tested from this batch was a tad faster than AMAX. (all factory loads here)
I have new actual values written down and I'd have to dig. But I recall 500 yds changed to 15 MOA. 750 yds my old calc for AMAX stated 26 MOA, but I dialed to 29.75 MOA and lucky chance that was the required adjustment. 29/30 hits on the gong. I thought I would try to dial in better by 1/4 MOA about 3 rds in and that was the miss, went back to 29.75 and kept banging.
123gr ELD Match BC Discrepancy - NugginFutz - 04-26-2019
newb Wrote:Not sure if this will help for real world results vs stated info, but I would use the lower stated BC and here's why.....
I recall others a few years back saying AMAX needed to use lower BC for drop calc so I used that for the base BC which was said to use 0.42.
The trajectory didn't line up and I did do proper scope center to bore measurement. There could have been an error on my part somewhere, but I didn't look into it and just used the real world results as calc values to me are a starting point to get close and then map actual real world data, re-plot from there.
22" barrel. AMAX chrono'd pretty close around 2510 fps and my origial cal value I put 2500 before I had chrono data. 100 yd zero.
300 yds called for 4.82 MOA, I was 7 MOA. 500 yds called for 12.73 MOA (mine is 1/4 MOA increments) and 12.75 did perfect. This was the furthest I used AMAX for, I don't recall if 750 yds or not so I'll just say not.
Finally ran out of my AMAX stockpile and used the ELD last week or week before and don't recall that fps off the top of my head, but I think the ones tested from this batch was a tad faster than AMAX. (all factory loads here)
I have new actual values written down and I'd have to dig. But I recall 500 yds changed to 15 MOA. 750 yds my old calc for AMAX stated 26 MOA, but I dialed to 29.75 MOA and lucky chance that was the required adjustment. 29/30 hits on the gong. I thought I would try to dial in better by 1/4 MOA about 3 rds in and that was the miss, went back to 29.75 and kept banging.
The discrepancy with the Amax bullets (and apparently with several other poly-tipped bullets, such as the Nosler) was due to a phenomena known as aero-heating. Friction at high velocities caused the plastic tips to melt, resulting in a decaying BC as the drag increased with the melting tips.
The ELD tips eliminated that issue. Further, where the BC's were previously calculated, Hornady now publishes their BC's resulting from direct measurements using their doppler radar system.
In other words, newbie, the data on the new ELD boxes is quite accurate.
123gr ELD Match BC Discrepancy - newb - 04-26-2019
NugginFutz Wrote:The discrepancy with the Amax bullets (and apparently with several other poly-tipped bullets, such as the Nosler) was due to a phenomena known as aero-heating. Friction at high velocities caused the plastic tips to melt, resulting in a decaying BC as the drag increased with the melting tips.
The ELD tips eliminated that issue. Further, where the BC's were previously calculated, Hornady now publishes their BC's resulting from direct measurements using their doppler radar system.
In other words, newbie, the data on the new ELD boxes is quite accurate.
If one watches their sales pitch video for their new A-TIP they talk about this bullet supposed to greatly reduce the BC variations found in standard production bullets. Which I believe would mean the likes of ELD, etc have noted BC variations +/- advertised value.
If I recall correctly reading various places the AMAX tip softening with some deformation didn't happen until at least 600 yds and with velocities higher than Grendel at that distance. Some long range guys claiming they didn't notice anything at 1,000 yds. But none the less that is a dead horse.
I dug up my values and 10 ft chrono data agrees right in there with the ELD velocity stated on box, at least with the rounds I ran chrono on. According to the trajectory simulator ran just now, with that Hornady stated G1 BC and my altitude etc correction, MOA drop at 500 yds should be 9.65. My actual drop was 15 MOA. I don't have doppler radar to track down range. The best I can do is state the data I personally collected.
The only thing left I could re-verify on my end to rule out would be 100 yd scope box test.
123gr ELD Match BC Discrepancy - NugginFutz - 04-26-2019
newb - I can't speak to your experience, but let me share mine.
Last weekend I took my 22" Bull Barrelled BHW out for a romp. I sent some rounds down range, using the ballistic computer's wind and elevation calls for dialup and wind holds. I was meticulous about the data I entered, regarding measured wind, temperature and elevation. MV was 2570, from the most recent outing's chronograph readings. I entered the .506 G1 BC for my 123 ELD's, as indicated by the box, the Hornady website, and the the ballistic calculator's internal library.
I checked zero @ 100, and dialed up in the calculated elevations at various distances and was able to put first round hits on almost every target. Other than changes to my wind holds, I did not deviate from the drop chart generated by my app.
These are some the hits on steel out to 1000 yards.
[ATTACH=CONFIG]14179[/ATTACH] [ATTACH=CONFIG]14180[/ATTACH] [ATTACH=CONFIG]14181[/ATTACH]
My come ups were 2.0 mils @ 400 yards, 6.6 mils @ 800 yards, and 9.5 mils @ 1000 yards. Wind was 15 mph L-R, gusting to 25. This particular range is @ 6600 ft ASL.
A quick check for a 500 yard drop in MOA shows I would have used a 10.4 MOA come up, somewhat more than your calculated hold of 9.7, but reasonably close.
What I'm trying to illustrate is that IF your data is good, a quality calculator can put you on target with a fair measure of accuracy. Mind that fact that it is a model of a real world situation, and the deviations from the real world come from primarily from data entry errors.
So, if you are getting a 15 moa drop at 500 yards, and assuming that your 2510 MV is accurate, I would have to come to one of two possible conclusions: 1) we are shooting two different bullets, or 2) we are measuring our drops differently (scope error).
While #1 is possible, it is unlikely that the boxes are mismarked. The would leave me suspecting an issue with the scope. I have checked my scope, using a technique described by Bryan Litz, called the Tall Target Test. This, combined with the well known Box Test, has given me confidence in the scope mounted on this particular rifle.
As I said, I can't speak to your situation, directly, newb, but my experience tends to align with the stated BC of the round in question. So there you have it - we have two disjointed experiences.
123gr ELD Match BC Discrepancy - mel - 03-01-2020
ive had no issues using the .506 data even when pushing past 1000 yards bot with my digital scope which does all the adjustments for me after ranging target ( i.e cheating) , or using strelok/ or the atn balistics app with my glass scope
[video=youtube;33LKATuXx04]https://www.youtube.com/watch?v=33LKATuXx04[/video]
only time i had issues is when i was using the wrong scope height numbers