Need help with Hornady 178 ELD-M for 308.

[rustyshackleford]

I wouldn't be concerned with the twist. Being sufficiently fast is all that matters. My 308 has a 1/9 twist and shoots heavy and light bullets fine. Considering you are getting good groups with the 175 SMK I'd assume your loading technique is fine and your rifle just doesn't like that bullet. I would just try other options. 169 smk, 175 berger, and 168 berger hybrid are all good options of trying to compete in Tac division. If you aren't worried about any rules you can also try the 185 Berger juggernaut. You might buy some factory hornady and see how it shoots if you are dead set on this bullet. I'd investigate the G7 form factor first. I don't think it's particularly good

 

[xsn10s]

If he ordered a 1-12" twist it's marginally stable. I ran it through Berger barrel twist calculator.

 

[dragon798]

I've used Bison Ballistics Gyroscopic Stability Calculator whereas all data about the bullet weight, caliber, length, twist of barrel you intend to use along with the speed I intend to obtain and it gives me the Sg. I normally go with 1.3 to 1.49 where it shows the best accuracy. Hasn't failed me yet. Used it to get me out to 1 mile with a 6.5x47 at Black Bear shooting complex. But that's me. Just giving my HO.

According to Bryan Litz, 1.5 or above for stability factor. Below 1.5 is marginal. Berger twist rate calculator is my go to. I trust the science from the guy that designs the bullets.

 

[xsn10s]

44-45 grains of Varget, CCI LRP, 2.80. I run this load in multiple 308s with 10 twist barrels and shoots sub MOA all day long. Make sure you're starting with a clean barrel and not something fouled from another bullet manufacturer. Different copper alloys can cause accuracy issues when switching. The 178 ELD-M and the 178 AMax have always been very easy for me to load and get accurate quick.

I haven't found a problem running SMK's and ELDM's through the same barrel with no cleaning. But cleaning was something I agree that you might try. If that doesn't work then yeah maybe your barrel just doesn't like the 178 ELDM. Use what works.

 

[JAYgs8163]

According to Bryan Litz, 1.5 or above for stability factor. Below 1.5 is marginal. Berger twist rate calculator is my go to. I trust the science from the guy that designs the bullets.

Like Hornady? They designed the bullet and recommend 12 twist or faster. All depends on Elevation also.

 

[dragon798]

Like Hornady? They designed the bullet and recommend 12 twist or faster. All depends on Elevation also.

Exactly, 12 or faster. So as I said earlier 12 twist is probably the minimum. Saying the 178 needs a 12 twist is not true. It needs minimum of 12, and faster should be better. Furthermore, saying 1.3 or 1.4 is stable is also not true. It may shoot well, but only has marginal stability. And it doesn't matter what elevation, 1.4 SG is marginal at any elevation. Now a bullet that achieves 1.4 at sea level will likely be 1.6 at say 3000', and that is stable.

 

[DoneNOut]

IMR4064: 42.3 - AVG: 2685 - Grp: 1.75" (Slower??) SD: 7, ES 17

This is a great indicator you are at the wall of performance out of that powder/bullet combo. Your velocity dropped and your ES/SD tightened. If you aren't seeing pressure, this would be one to group a couple more times with some varying bullet seating depth.

 

[Ikeman83]

Just came in to post that twist rates are given in "Rotations" per "Length of Barrel". A "12 twist" is slower than a "10 twist". The "10 twist" will rotate 1 & 1/6th times in 12 inches compared to once for a "12 twist".

Hope that helps.

 

[DoneNOut]

Just came in to post that twist rates are given in "Rotations" per "Length of Barrel". A "12 twist" is slower than a "10 twist". The "10 twist" will rotate 1 & 1/6th times in 12 inches compared to once for a "12 twist".

Hope that helps.

WUT? 1-10T means the bullet is spun 1 time in 10". 1-12T means it is spun 1 time in 12". Where did you get "length of barrel?"

 

[SIRGARRETH]

HI All. Thanks for the replies.
Barrel is a 1:10 twist. I am not set on that bullet at all. I just purchased 2 boxes just because of the reviews and I figured I should be able to get them to shoot.
I do not shoot in any competitions at all or hunt. This is just for fun.
I am going to try this load again, but will change the COAL from 2.8 to 2.84. That should bring it to 0.020" off the lands. Maybe 0.060" off the lands was too much?

IMR4064: 42.3 - AVG: 2685 - Grp: 1.75" (Slower??) SD: 7, ES 17
Will also try going up on Varget. Maybe 43.6 to 44.0?

 

[Ikeman83]

WUT? 1-10T means the bullet is spun 1 time in 10". 1-12T means it is spun 1 time in 12". Where did you get "length of barrel?"

10 inches of _ _ _ _ _ _.

Fill in the blanks of what you think the bullet is spinning in.

 

[xsn10s]

HI All. Thanks for the replies.
Barrel is a 1:10 twist. I am not set on that bullet at all. I just purchased 2 boxes just because of the reviews and I figured I should be able to get them to shoot.
I do not shoot in any competitions at all or hunt. This is just for fun.
I am going to try this load again, but will change the COAL from 2.8 to 2.84. That should bring it to 0.020" off the lands. Maybe 0.060" off the lands was too much?

IMR4064: 42.3 - AVG: 2685 - Grp: 1.75" (Slower??) SD: 7, ES 17
Will also try going up on Varget. Maybe 43.6 to 44.0?

That all depends on any pressure signs. but if this is all for fun then I'd just load 175 SMK's and have fun. Why waste components and time?

 

[SIRGARRETH]

It is just for fun, but it also gives me something to do.
I use 147 ELD-M on my 6.5 Creedmoor. My three Creedmoor rifles all give me 0.4" groups all day long.
Will try a few more things and see what happens. If those don't work, then oh well. Will keep shooting the SMKs.

 

[Ikeman83]

If the 178s aren't working well for you I'd sell them and reinvest in the 175 smks