.308 - 178 ELD-X Accuracy Issues

[rijndael]

I thought I had a good 178 ELD-X load developed but I'm finding the accuracy goes downhill rather quickly. It goes from < .5 MOA to 2+ MOA as my barrel heats up. The first few groups are always good.

I'm not cooking the ammo in the chamber.

I don't believe it's a gun (or barrel mirage) issue because if I switch over to my 175 SMK load, it shoots as it should, tight groups. The gun is a 700 5R 20" - pillar bedded in a Grayboe stock.

Any ideas on what would cause this?

 

[Raptor]

Have you tried a different lot of bullets??? I had a lot of 162 AMAXs that were bad. I changed the barrel over the damn things!!

 

[rijndael]

I have not. This was my first box. I was holding out to to see if they shot before I made a bigger investment.

 

[Texas10]

I'd like to offer a couple of suggestions to think about.
Is it possible your load is on the upper edge of a node?
Have you tried reducing the charge by one or two tenths of a grain?
Is the air temp significantly different now than when you developed your load?
By how much do your velocities change between the first groups and the later ones?

I hope this helps.

 

[Richard Coody]

rifle will tell you what it likes. if it is MKs then i would stick with them

 

[rijndael]

Is it possible your load is on the upper edge of a node?

It's smack in the middle of a .75g wide node.

Have you tried reducing the charge by one or two tenths of a grain?

Not yet, but that's next, if I buy another box of bullets to keep trying to find a load that works. It hasn't been easy with these bullets.

Is the air temp significantly different now than when you developed your load?

No. It's an indoor 100Y range, climate controlled.

By how much do your velocities change between the first groups and the later ones?

I don't know if I have that data, I'll have to go check.

Thanks for all of the ideas/suggestions.

 

[rijndael]

rifle will tell you what it likes. if it is MKs then i would stick with them

Yea, I'm wondering if it's just time to move on. The downside is I need the better BC bullets to get to 1K with my 20" barrel and still be supersonic. Next on the list is the 195 TMK and the 185 Jugg.

 

[Richard Coody]

try the lapua senar 155's or the berger 155.5 fullbore. work up to 47 gr. varget. should get you to

 

[rijndael]

Already there, I'm also working a load with Scenar-Ls.

I was shopping a while back and the price of $300/1K was too good to pass up.

 

[Rodney]

I’ve been trying these bullets myself and found them to be finicky. My go to powder IMR 4064 didn’t group well so I tried reloader 15 and found the accuracy I was looking for. Maybe try a different powder. Good luck with your testing.