Load Development Help

[TSpork]

So last Thursday I decided to go into work late and do a little shooting before work. This is my first foray into long range precision reloading, so any help would be appreciated.

Cartridge: .308
Brass: Lapua Virgin
Powder: Varget
Bullet: 178 ELD-M
Primer: CCI 200

It was 64.4 degrees with a slight wind. I began by firing 10 shots loaded with 41.0gr of Varget to zero my scope.

I’m trying to see what powder charges I should be exploring. I loaded 3 rounds each from charges 41.0-45.0 in 0.2gr increments. All rounds were loaded to be 0.020” off the lands. Each of these were shot over a labradar, and the chrono results are available unless I screwed up and forgot to hit arm, or pushed the gun too far forward and It didn’t trigger the labradar.























On 45.0gr, I didn’t have a chance to take my 3rdshot because it’s about 30 minutes between cease fires and I didn’t want to waste more time before work. I also had the same amount of rounds loaded with a 175 SMK, but I didn’t have time to shoot those because of time.

*When I got home, I found my bipod was a little loose, so that may have caused accuracy issues. Especially towards the end.

**Some brass were loaded (~45), then had the bullets pulled and had an expander mandrel ran through. I’m not sure if those can be attributed to the velocity spreads.

***Prior to last Thursday, I’ve fired 160 shots through the gun, so I don’t think my barrel is speeding up. This is my first precision gun, so I’m still really new at this.

Here is a link to a previous thread I started about reloading:
https://www.snipershide.com/shootin...loading-setup-procedure.6916296/#post-7445491
https://www.snipershide.com/shooting/threads/bullet-seating-trouble.6919397/#post-7445493

Do you see any nodes I should focus around? I’m not 100% certain what I should be looking for. I think I should explore around 43.4-43.8 because the shots seem to group in the same relative area in relation to other charges. but any thoughts would be appreciated

 

[TSpork]

I just realized that my pics are ridiculously large. I just left to go to dinner, but I’ll resize them when I get back

 

[ken4570tc in WY]

It's getting to late tonight for me to help you with my .308 experience when I was shooting 1000BR 10 years ago but I'll have time to look over my load development binder tomorrow and report back.

 

[TSpork]

It's getting to late tonight for me to help you with my .308 experience when I was shooting 1000BR 10 years ago but I'll have time to look over my load development binder tomorrow and report back.

Thank you! New to precision shooting and reloading for precision, so any tips, pointers, sage advice would be helpful. I also realized towards the end, I was really rushing my shots. I caught myself getting off the gun right after pulling the trigger a few times. Going before work probably wasn’t the best idea I had

 

[ShtrRdy]

I would go for the 43.6 load. It had a great group and the sd looks good.

 

[ken4570tc in WY]

Thank you! New to precision shooting and reloading for precision, so any tips, pointers, sage advice would be helpful. I also realized towards the end, I was really rushing my shots. I caught myself getting off the gun right after pulling the trigger a few times. Going before work probably wasn’t the best idea I had

That stuff won't get better with age!

 

[TSpork]

I would go for the 43.6 load. It had a great group and the sd looks good.

Would I need to increase the load slightly since this brass is Virgin brass and might be a little undersized?

 

[TSpork]

That stuff won't get better with age!

Sometimes it's good to be 28

 

[TSpork]

Also, I have all the brass sorted still into the charge weights they were fired in. I can post photos of the primers/brass for any of the charges if someone wants to see them

 

[ShtrRdy]

Would I need to increase the load slightly since this brass is Virgin brass and might be a little undersized?

You'll need to try a couple steps on either side of 43.6 with once fired brass. Recently I needed to drop my charge weight by 0.3 gr, when changing to once fired brass. But I also started using a different lot of powder too so that may have influenced my result.

 

[Billiam1211]

Well the good thing is you have quite a bit of data to work with and if you want you can use the Scott Satterlee method and basically pick your group based on the lowest SD. If you plot your SD numbers on a line graph you'll notice that they probably incrementally change as you approach accuracy nodes and scatter nodes. SD is important in PRS because as you engage targets at distance, if you have a swing of 30fps it can result in a miss. A rifle that shoots 1/2 MOA groups at 100 yards and has a SD of 5 is going to be way more accurate at long range than a rifle that shoots 0.2 MOA groups at 100 yards but has an SD of 15.

My bet is that if you load a few groups in those super low SD charge weights, you'll probably find they shoot super well and those are in fact your accuracy nodes. Watch 6.5 Guys 10-Round load development on YouTube, they go into great detail on this.

 

[spife7980]

I disagree^^
I think youll find that those super low SD arent replicable and the number will increase with a larger sample size.


Pics of the groups all together in one image will be easier to decipher than the individuals.



Since this is virgin brass I would go 42.4, it appears pretty stable. Get it all formed and then you can begin development in earnest. Youll probably find that once formed youll need to add a couple tenths to it to get back to where you were at with virgin brass.

 

[TSpork]

I disagree^^
I think youll find that those super low SD arent replicable and the number will increase with a larger sample size.


Pics of the groups all together in one image will be easier to decipher than the individuals.



Since this is virgin brass I would go 42.4, it appears pretty stable. Get it all formed and then you can begin development in earnest. Youll probably find that once formed youll need to add a couple tenths to it to get back to where you were at with virgin brass.

When I get home I’ll see if I can make them all into one pic.

Do you mean 43.4?

 

[spife7980]

When I get home I’ll see if I can make them all into one pic.

Do you mean 43.4?

Nope, 42.4, they are centered in pretty much the same area and Im willing to bet that those two shots that are away to the left are likely due to the virgin brass varying neck tension or you pulling them yourself.

 

[ken4570tc in WY]

+1 on Spife7980,

He knows his stuff! Two and three shots doesn't provide enough data to be statistically significant or usable. You pretty much need a minimum of ten rounds per load or more.

I searched through my load development binder for my .308Win 1000BR shooting days and found that I ended up with Lapua brass, Federal 210M primers, H4350 powder and SMK 175 bullets. At that time, Varget was noted for lot inconsistency and the H4350 was just starting to be recognized as a good competition powder. My testing showed that the bench rest/competition primers were measurably out performing standard primers but I had no discernible difference between CCI vs. Federal. I started with SMK 168gr bullets but had trouble with 1000yd stabilization. At the advice of a top shooter I moved up to the heavier 175s and fixed the problem. If I were you, I'd switch over to BR-2 or 210M primers, load ten each of 42.3, 42.4, and 42.5 grains of Varget and collect the data. A good reference read on the .308 can be found at <http://www.6mmbr.com/308Win.html>. Because of the popularity of H4350, it is getting difficult to find, it comes and goes in waives. More recent studies have shown it to out perform Varget for temperature stability. Before experimenting with different bullets, try testing various seating depths and don't be shy about it. I believe it is Berger that suggests you can try seating groups of reloads and vary the depth by .020" out as far as .150" to search for sweet spot/node.

 

[TSpork]

Thanks guys! This is why I ask the experts! I still have like 80 virgin cases plus the loaded 175 SMKs that vary in charge weight that I haven’t fired yet.

I think I’m going to load those virgin cases at 42.3, 42.4, 42.5 and some more at 43.5, 43.6, and 43.7. I’ll load 10 at each charge weight to get a better sample size.

I’ll fire those along with those SMKs to get lot of data on my next outting.

How does that sound for a plan?

If I get a chance maybe I’ll try to load a few of my once fired around the same weight too, but not sure about that one. Might get too confusing with so many different variables to keep track of at once