Thread: 308 ELD-X 178gr experiment - bullet or powder manufacturer?

Did a test of the Hornady load data versus the Hodgdon load data today. Was interested in “who to believe”, bullet manufacturer or powder manufacturer?

Rifle: Tikka T3 .308
Projectile: Hornady 178gr ELD-X
Powder: ADI AR2206H (H4895)
Primer: Federal 210
Brass: Lapua
COAL: 2.917”

I’d done a normal work up with the Hornady data to book max a while ago (40.7gr H4895). I knew I was safe at this weight but wanted to test past this point to see if I could find an accuracy node within ±5%. My selected COAL is 0.117” higher than the SAAMI standard of 2.800” so that gave me a bit of wiggle room.

The Hodgdon load data for 175gr and 180gr bullets had max loads of 42.7gr and 42.5gr respectively. I checked the 175gr bullet – the Sierra MatchKing HPBT – the length is all but identical to the ELD-X bar the plastic tip. So that was what I set my test maximum to – 42.7gr.

The photo below shows the results at 40.7gr on the left, 41.7gr in the centre, 42.7gr on the right.

Attachment 96754

Very clear ejector mark and swipe and flattened primer at 42.7gr. Not quite so pronounced at 41.7gr, but there’s an ejector mark and a slightly flattened primer. The Hornady book max of 40.7gr shows neither an ejector ring, nor a flattened primer.

I had read the Hornady paper that said there were pressure issues with the 178gr ELD-X if the reloader used data for other bullets of a similar weight, specifically the ELD-M. This seems to have been confirmed by these results – use the powder manufacturer’s data and you’ll get a surprise if you don’t work up properly. My shooting buddy also got pressure signs at a little over Hornady book max and ended up dropping the ELD-X as he couldn’t get the velocity he wanted.

I’m happy with the velocity I’m getting – from the drop tests I did last week its quite a bit higher than the book velocity and the Quickload velocity. Some more testing to be done once I’ve done a ladder test in 0.1gr increments from 40.7gr. As soon as I see an ejector imprint, I’ll stop.

The 178gr ELD-X load data was released by Hornady as a PDF on their website for a while, now they’ve taken it off and you either have to buy the book, or google an image someone has posted. Or ask me for the PDF. From what I’ve read, a lot of blokes have gone with the Hodgdon data for H4895 and the 175gr bullet and come unstuck with high pressures. Proves once again the importance of working up and not assuming anything as a given.

I can't get the edit function to work on this forum. Comes up with no text to edit, and no option to delete the message.

Another go at getting the photo to work:

Could you tell me what is the Hornady starting and max data for AR2208/Varget?
I'm using 42.5 grains of 2208, same case and primer as you, I could (and have) gone a bit higher but best grouping was at 42.5. I don't know velocity but drop at 300 was less than expected.
Cheers!

I'll try and send you the PDF @Cigar.

Likewise, the drops at 300m last week were HEAPS less than the ballistics app calculated for the book velocity. So much less drop that I didn't believe it at first and did it again, with the same result. All very odd.

Am going to do some water capacity tests with the different brass I've got, Lapua, ADI, Winchester, see if I'm using cases with significantly less capacity than SAAMI standard.

Originally Posted by Flyblown

I can't get the edit function to work on this forum. Comes up with no text to edit, and no option to delete the message.

@Flyblown,

No rhyme or reason to why, but I get the same from time to time. Sometimes it helps just pressing edit, and just count to whatever - the text eventually appears in the edit window... sometimes.

What barrel length do you have Flyblown and what speeds are you getting?

I have the standard 22.5" Tikka barrel and the drop tests calculate to ~2700fps vs a book value of 2450fps.

That's using the Strelock+ trajectory validation function and checking it in the Hornady 4DOF calculator online.

That's a huge difference in velocity and I don't really believe it to be honest, still looking for reasons it could be wrong. I did three drop tests, all came out the same. Zooming back and forth on the bike, measuring, shooting, measuring, shooting. Like, wtf is going on here? I mark each target with the anticipated drop before I shoot and I could see they were hitting well high from the shooting position.

Originally Posted by Flyblown

I'll try and send you the PDF @Cigar.

Likewise, the drops at 300m last week were HEAPS less than the ballistics app calculated for the book velocity. So much less drop that I didn't believe it at first and did it again, with the same result. All very odd.

Am going to do some water capacity tests with the different brass I've got, Lapua, ADI, Winchester, see if I'm using cases with significantly less capacity than SAAMI standard.

Got it, thanks!

Strelok reckoned I need to dial 14 clicks at 300m if velocity was 2500fps, but I was hitting very high at that, 7 clicks was probably close. Scope could be doing more than a quarter MOA per click, though is a new Leupold so shouldn't be too far off. Next time at the range I'm going to stay at my 200m zero and measure actual drop at 300 and remove any scope effect. Then I'll see how many actual clicks I need to dial on my scope to be bang on at 300, which is of more use to me than theoretical clicks at an estimated velocity.

That backs up the info on Terminal ballistics where Nathan has found that with the ELD-X he had to back the loads off from what he was running with ELD-M. From what I understand it's to do with the X having a heavier jacket giving greater resistance to engaging with the rifling.
Zq

What BC did you use in Strelock+?
Hornady list a G7 BC of 0.275 but Applied Ballistics list a G7 BC of 0.284, this would have been tested by Brian Litz and his team so will be closer to the truth.
Usually the quoted BC's from bullet manufacturer's drop when tested by Applied Ballistics but not in this case.

BTW the 7mm 150Gr ELD-X tests higher than Hornady's quoted BC too.

Ive gotton to the point where with any new load and thats not often now I zero at 100 and over the chrony do a drop chart out to 4 or 500 m. I then set my preferred zero and do a quick reshoot at say 300 and 500. Im yet to find a ballistic calculator that predicts the drop chart accurately across the full range.
For longer distances I have loaded the figures Ive got into an xl spreadsheet and produced a predictive decay curve that appears to be accurate.

Originally Posted by winaa

What BC did you use in Strelock+?
Hornady list a G7 BC of 0.275 but Applied Ballistics list a G7 BC of 0.284, this would have been tested by Brian Litz and his team so will be closer to the truth.
Usually the quoted BC's from bullet manufacturer's drop when tested by Applied Ballistics but not in this case.
BTW the 7mm 150Gr ELD-X tests higher than Hornady's quoted BC too.

I’ve been using the Hornady numbers.

Reason being they switched to doppler radar for the ELDs and that’s a highly accurate method. I hear you on Litz’s numbers. At some point I considered changing it but clearly never got round to it because what in Strelock now is the original Hornady number. I agree that traditionally Brian Litz has pooh-poohed many BC claims with his methods, Nosler being in his sights in particular. In this instance I have found the ELD-X to generally drop less than I am expecting. But not this much less, for the .308. Spent a fair bit of time on it this week but I need to adjust the load because a full case of 2206H, a 178gr bullet and a light rifle is making recoil quite lively and to be honest I’m not shooting it very well, 1.5MOA at best. Will revert to 2208 and see how I fare. Can’t do anything in these bloody gales though.

What I would say in response to @Marty Henry is that yes, there always seems to be some variability between chrono, ballistic app, manufacturer’s claimed numbers, and drop tests. I have found that by validating the 300m, 400m and 500m trajectory in Strelock, and generating a corrected muzzle velocity, from that point forward the load delivers accurate shooting for medium-range hunting purposes.

I have found out that I’ve needed to check each batch of re-loads. For every 100, 10 go into two 5 shot groups at 300m for am accuracy and drop test. Assuming roughly equal environmental conditions and me being on form there’s always a little bit of variability especially from batch to batch of ADI powder.

I like the sound of a predictive decay curve though... once I’ve worked out what one of those is. I think I need a predictve decay curve for my body, as the rate at which things are wearing out is changing this side of 50, alarmingly fast!

plurry interesting you got ejector marks yet the primers look fine......faark Ive had then that flat its not funny back when I got shops to load for me.... normally by the time I would get ejector mark like that my primers are well showing flatening.... if you have got a known drop you COULD go to huntingnut and use pointblank online...keep changing your velocity figures or if thats known your bc etc can be changed...sooner or later you will hit jackpot.

My std 308 load I have used for a long time , is Lapua brass , SMK 175gr , CCI BR2 primers & 45gr of ADI 2208/Varget , I get 2700fps out of a 26 inche barrel , and I mention it because instead of the Seirra SMK 175gr bullet , guys substitute a Amax 178gr , which would be virtually the same as your eld ?

Later Chris

Originally Posted by ChrisF

...and I mention it because instead of the Seirra SMK 175gr bullet , guys substitute a Amax 178gr , which would be virtually the same as your eld ?

@ChrisF as per @ZQLewis in post #9 above, the AMax is not similar to, or a straight replacement for the ELD-X due to proven pressure problems at higher loads due to different bullet construction. AMax is similar to the ELD-M. It is written up by Hornady in a paper they published which I can’t find now. Very important not to switch bullets of a similar weight without working back up. N Foster reached this conclusion too and wrote it up in his book.