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.