Powder choice, bullet, and group size.

While I do not have any clue on how you loaded the ammo you have been shooting, especially since I cannot find any loading data for that combination. I would think, and remember, this is a Blonde thinking, that possibly there is no published data for this combination, at least I could not find any and whatever load you are using is not recommended by anyone. As such you are delving into uncharted and dangerous territory.

There are a few temperature stable powders out there. Here is an excerpt from Long Range Hunting from Feb 16, 22

Feb 16, 2022 — The Hodgdon "Superformance" powders are all designed to be pretty temp stable. Varget, H4831, H4350, H1000, etc. You can't go wrong with those for temp ...

Gunpowder charts for temp sensitivity and burn rates
Feb 16, 2022 — The Hodgdon "Superformance" powders are all designed to be pretty temp stable. Varget, H4831, H4350, H1000, etc. You can't go wrong with those for temp ...


Gunpowder charts for temp sensitivity and burn rates
Jan 26, 2021
Temperature stable powders | Long Range Hunting Forum
Jan 1, 2018
Stable powders | Long Range Hunting Forum
May 9, 2011
Temperature sensitive Powders | Long Range Hunting Forum
Dec 4, 2023
More results from www.longrangehunting.com

Delving further into this issue, I have not been able to find any published data for 7mm/08 with 150 gr ELDX bullets in the Winchester, Hornady or Nosler loading data that recommends Staball with the Hornady ELDX bullet. Even the Hornady manual lists Reloader 17 as their recommended powder with the ELDX. The other manuals recommend 7mm/08 with Barnes TTSX, Sierra HPBT and the Nosler Ballistic Tip or Partition with any variety of powders with H380 being the most accurate tested.

Now after all of this, the Staball HP loading data shows the 150 gr Barnes TTSX and Sierra HPBT as the recommended loads. Both are fine bullets that will do everything that the ELDX will do, and probably better. Of the two I have much experience with the Sierra HPBT across a variety of calibers and powders and that would be my preference.

I have found over the past 55 years of loading my own ammo most of the time that if I can't find the powder/bullet combination in any loading manual, especially that of the bullet manufacturer then, it's best to find another combination.
This is from Hornady's 11th edition manual, so I'm not going on an unknown or potentially dangerous venture lol. Granted I have been only loading my own ammo for the last 10 years, I always take safety as a concern and don't load at above recommended charge weights.
 

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As with anything else, YMMV. It would be best to find out what works for your rifle using different powders and charges, bullets, seating depths, etc., not other people's loads and rifles. I prefer the -M over -X.
I wasn't asking for anyone's pet loads, just asking if you abandoned the bullet or powder first. I understand there is a whole lot of variables that go into making accurate ammo. I suppose I have been really lucky in the rifles I have loaded for that starting at published coal, and starting at 90% charge weight has gotten me a good start to fine tune. This is the only combo that has produced groups in the 3" range for this rifle, but I have never shot this bullet or powder before.
 
This is from Hornady's 11th edition manual, so I'm not going on an unknown or potentially dangerous venture lol. Granted I have been only loading my own ammo for the last 10 years, I always take safety as a concern and don't load at above recommended charge weights.
I didn't have a Hornady Manual, but checked the reloading data on the web site. Didn't find any data for the combination. I have never got Hornady bullets to shoot as well as others, for me most notably Nosler and Sierra. Doesn't matter what caliber or type of bullet, just don't group well for me in anything I have tried them in from MSR's to match rifles. I have a lot of boxes of partially empty Hornaday bullets sitting on the shelf. Tried them and couldn't get them to shoot up to my expectations. Then again, I am a fussy old bitch. 🤣
 
Since the bullet is the main thing I tend to pick a bullet I want to shoot and try and find a powder that works. I did some loading in 7/08 with 120,140 ballistic tips and staball. It was fast but accuracy was meh. Varget is one of the most stable powders out there and tends to work well in 308 sized case.
 
I wasn't asking for anyone's pet loads, just asking if you abandoned the bullet or powder first. I understand there is a whole lot of variables that go into making accurate ammo. I suppose I have been really lucky in the rifles I have loaded for that starting at published coal, and starting at 90% charge weight has gotten me a good start to fine tune. This is the only combo that has produced groups in the 3" range for this rifle, but I have never shot this bullet or powder before.
I did not recommend abandoning either one because I have no clue how you developed your load. As I noted, as with anything else, YMMV. As you indicated, you are lucky to be using published COAL and starting at 90% powder charge. I do not know if you have made any seating depth changes or what your accuracy node is at various powder charges.

So you know that at least Hornady tested the bullet/powder combination on their 11th ed (I have the 10th ed). However, they do not indicate which powder is the most accurate. I do not know if they still do, but I have a Nosler 6th ed showing which powder is the most accurate. I wish most reloading manuals would do the same. Regardless, it is just a reference/baseline.

Nosler.jpg


I prefer to measure CBTO over COAL, but I track both on my load development tracking log and the distance to the lands. I do not chase the lands but prefer .020" +/—.005" off them.
 
For me I would try different bullets weights and styles 1st.
Generally you can find what powders do well with different case capacity's.
For instance 30-06 sized cases do really well with 4350 and 4831 powders.
So if you find a lot of people posting they are having good success with the same powder like varget in .308 and you're not getting good groups then I would be trying a different bullet or weight.
Seating depths is not really going to change group sizes as much as bullet weight, style
and powder choice.
For me it's the bullet that the gun will like or not regardless of powder. It may like a different powder better but generally I can tell with a ladder test if a gun likes a certain bullet pretty fast.
Having a choice of powders and bullets on the bench helps a lot though. But that comes from reloading a lot of different cartridges over many years. Anyway now I'm just rambling on.
 
I find Staball 65 works best with the heaviest bullets.. Wouldn't surprise me if the 162 gr bullets shot lights out. I have also found ELD X bullets to be more difficult for me to shoot great. The ELD M on the other hand have always been easier to get to shoot great. the 162 ELD M in a 7-08 would be awesome.
 
This is where QuickLoad shines.
I can run what-ifs with it to see which powder gives the following at once:
Max MV
at my case capacity
with .XXX of seated bullet bearing
At my barrel length
at SAAMI max pressure
at 100-104% load density

If the numbers validate across a chronograph, I don't blame the powder for poor results, as this is the best I'm gonna get.
Then there may be something less than optimum about the bullet w/resp to the bore/bore interface.
If full coarse seating testing is already completed, change the bullet,, Start over.
Otherwise back off the charge a bit, run full coarse seating testing, redevelop powder at best seating.
If results still suck, consider primer/striking testing.

IMO, a coarse seating test and a primer swap test are prerequisite to tuning.
Both can be done while fire forming brass to stable, and it can save a lot of tail chasing later.
Once below 1/2moa precision, do fine seating and neck tension testing for tightest group shaping.
I have a question: what is the "mission" in your selection of bullets and powders? If you are looking for hunting, paper poking or steel clanging wouldn't stability, accuracy and dependability be more important than speed?
 
The guy said he was using the 150 eldx. So I assume it's for hunting. In that case I pick the bullet I like and have experience with. Bullet performance is most important to me. A small increase in accuracy is not worth the trade off in bullet performance for me. I may try a different weight bullet of the same design. Only if I cannot get acceptable accuracy will I try another bullet. Terminal performance, accuracy and being in the speed range for the bullet I find appropriate.
 
I went with the 150 ELDX because it was readily available in my area. I'm just hunting deer. My goal is to find a load that provides a decent max point blank range and hopefully that can be achieved at around 300 yards and also keep wind drift to a max of 4"-6" with 10 mile wind in that 300-350 range. I already bought the bullets so I would like to try them. Unfortunately I'm also limited to max length because of using a pmag. I can't get it approved with the accountant to fund a different bottom metal before the holidays lol. I'll try and use a couple different powders and see if I can get lucky, if not I'll just get closer.
 
I went with the 150 ELDX because it was readily available in my area. I'm just hunting deer. My goal is to find a load that provides a decent max point blank range and hopefully that can be achieved at around 300 yards and also keep wind drift to a max of 4"-6" with 10 mile wind in that 300-350 range. I already bought the bullets so I would like to try them. Unfortunately I'm also limited to max length because of using a pmag. I can't get it approved with the accountant to fund a different bottom metal before the holidays lol. I'll try and use a couple different powders and see if I can get lucky, if not I'll just get closer.
I understand you are limited with mag clearance, but did you do a seating depth test or not?
 

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