Which Charge Weight would you pick based on these results?

Sooner Sniper

Sooner Sniper

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#1
Working on initial load development for a new rifle. Barrel has a little over 200 rounds down the tube. My current thinking is to run seating depth tests with 41.0 gn and 41.8 gn loads. In a previous test I tested 40.9 and 41.0 loads and the ES/SD results were almost identical to the 41.1 gn load shown here with slightly lower velocities. I didn't have a lot of time yesterday, so I wasn't able to let the barrel cool down as much as I would have liked which likely effected the group sizes in the later groups as the barrel and the can were getting pretty warm. All groups are 5 shots at 100 yards with virtually no wind measured with Ballistic X. All test loads were seated .005 off the lands with Berger LRHT 140s. I'm curious which loads others would choose and why if they are different from the ones I'm planning to use. The extra shots between targets 8 and 9 are sighters. Thanks in advance for your thoughts!

Load Test Data 2.21.25.jpg
Load Test Target 2.21.25.JPG
 
#2
I’m not seeing any real differences, once you do bigger sets of data. Adding in your comments about barrel heat opening things up; I would pick 41.8 and do a slow 10 shot group on paper at 300. Data collection at 100 is where I do Rimfire. 300 paper shows differences better for centerfire. Also, very slight variations in position often obscure load differences on target.
 
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#4
All of those groups and SDs look like they’ll be plenty good for hunting and practical shooting. Probably fine for PRS as well. You aren’t likely going to make significant gains by shooting another 1-200 rounds trying to find the “perfect” load. I’m usually a fan of 41.3-41.5 grains of H4350 with a 140. That has consistently worked over like 5-6 barrels
 
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#5
Your charge increment of -0.1 gr is real tight and doesn't really correlate with the variations in point of impact. It looks like you have some variations due to moving from target to target. You also didn't mention if you shot round robin or not.

I would actually pick #5. The group size isn't the reason. The POI of 4 and 6 is the same and #5 group isn't bad and shift in POI is probably shooter. The SD's are good. Comments on the type are target above should be considered as a possible issue.
 
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#7
Personally, I would go for #4 based on group and I would discount ES/SD with such small data set.

In the past, I've had super ES/SD with initial 5 shot LD testing that increased quite a bit with larger data sets.

Also, personally I'd also look at something around 2,750 fps and see if you have an accuracy node (and I hate using that word "node") down there also.

Take it with a grain of salt...I'm not one of the reloading experts on this site.

Cheers
 
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#8
Sooner Sniper said:
Working on initial load development for a new rifle. Barrel has a little over 200 rounds down the tube. My current thinking is to run seating depth tests with 41.0 gn and 41.8 gn loads. In a previous test I tested 40.9 and 41.0 loads and the ES/SD results were almost identical to the 41.1 gn load shown here with slightly lower velocities. I didn't have a lot of time yesterday, so I wasn't able to let the barrel cool down as much as I would have liked which likely effected the group sizes in the later groups as the barrel and the can were getting pretty warm. All groups are 5 shots at 100 yards with virtually no wind measured with Ballistic X. All test loads were seated .005 off the lands with Berger LRHT 140s. I'm curious which loads others would choose and why if they are different from the ones I'm planning to use. The extra shots between targets 8 and 9 are sighters. Thanks in advance for your thoughts!

View attachment 8623801View attachment 8623802
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You're increments of .1 grs is too small for that size of cartridge, IMHO, making really hard to see what'd really going on unless you had a much longer string of POI's. For the future, I'd suggest .3 gr increments for that many POI's. With that said, I'd suggest you retest 4 through 6 . . . even #7 to see if there's anything there can can repeat. I think there might be something there.

What I like to look for in a series of groups is where the center of the mean average is at a pretty consistent position.
 
#9
No Caliber listed: But I assume it's a 6.5 Creedmoor.

No Barrel length listed, so it's hard to know if these velocities are good, bad or indifferent.

No purpose or mission for the load listed so it's hard to just pick one load for an unknown purpose. PRC use, or Punching paper & Steel, or Hunting, or what have you.

Shoot and See target are terrible for recording groups IMHO. If you have an in-home printer try some of these: Free Printable Targets

The 41.7- 41.9 Grain range of H4350 is a known accuracy node with 140 grainer's in many a 6.5 Creedmoor. BTW
 
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#16
41.5 is for thinner brass like hornady. The op is using lapua which is thicker and therfore powder charges need reduced. That's why 41.8 is near 2900 instead of near 2800. Show me some case head pics and I bet I can find you some ejector marks. I woukd suggest backing off also.
 
#17
No pressure signs at all. Have to admit the velocities are higher than what I expected and I would prefer them lower to extend the life of the barrel which was the reason I was going to do the seating depth work on the 41.0 load. The primers are CCI BR2s and neither the primers or the case show any signs of pressure.
 
#18
Looks like hodgdon says with a couple diffrent 140s and h4350 40g is about 2700 in a 24" at 60k psi. 2900 is starting to get to pressure shooting 123s in the 6.5 creedmoor. It's your brass though. You certainly aren't the only one out there playing "it's safe in my gun" on the ragged edge.
 
#22
You're three firings on brass into load development and still looking for power charge? Is there a 140 LRHT? I only see anything about a 144 LRHT?

Shoot your brass three times at 41.8. Throw it the trash because the primers are falling out.

How many giving advice shoot 6.5 creedmoor? How many are shooting 144s 2900fps in their 6.5 creedmoor? 😳🤣
 
#24
supercorndogs said:
You're three firings on brass into load development and still looking for power charge? Is there a 140 LRHT? I only see anything about a 144 LRHT?

Shoot your brass three times at 41.8. Throw it the trash because the primers are falling out.

How many giving advice shoot 6.5 creedmoor? How many are shooting 144s 2900fps in their 6.5 creedmoor? 😳🤣
Click to expand...
Sorry, the Bergers are 140 VLD Targets. Not LRHT. It was too early in the morning when I started this thread. Only the last firing was load development. The first two firings were all at 41.5 grains. I hadn't had time to actually start working on a load for this rifle yet, so I loaded at what had worked in my previous rifle that was unfortunately stolen.
 
#25
How close do you think you could replicate those results if you tried again?

Since 3-7 are basically going to probably switch places as far as "best group", I'd probably just pick #4 or 5 and run several more test groups with it.

Not that .1gr charge difference isn't cool to experiment with, but the changes in accuracy are going to be negligible...you are literally changing a quarter of a percent. Any perceived change on target is due to the shooter at that point (if you aren't shooting a bench rest setup).
 
#27
diggler1833 said:
How close do you think you could replicate those results if you tried again?

Since 3-7 are basically going to probably switch places as far as "best group", I'd probably just pick #4 or 5 and run several more test groups with it.

Not that .1gr charge difference isn't cool to experiment with, but the changes in accuracy are going to be negligible...you are literally changing a quarter of a percent. Any perceived change on target is due to the shooter at that point (if you aren't shooting a bench rest setup).
Click to expand...
Shooting was done from a bench with an Accutac bipod and a rear bag. Very confident in getting similar or better results. I was looking for a charge weight that would deliver consistently low SDs and ESs at +/- a grain. I was not really worried about shooting the tightest groups possible and I definitely pulled a couple of these shots.
 
#30
.1 grain increments is way too granular to try to discern a difference. In a 6.5CM a .3 gr increase should generally produce a 25fps increase. So you should be seeing a 8-10fps increase 'ish. But as you can see the correlation is loose and there's really no rhyme or reason to your right side column chart. It's just white noise.

2900 with 140's is really fast. You're probably going to wear the barrel faster which is going to create a slightly less consistent load/ barrel from batch to batch. You want to be looking for 2750 - 2800

.005" off the lands is too close to the lands. You should see about .002 - .003" of throat erosion every 100 rounds. You will also get carbon fouling that will change where you perceive the throat to be when you measure it by .002 - .005". This means that .005 jump you have will be more affected by fouling in the barrel than say a .020 - .030" jump. I would just set those Bergers to .020" jump and leave them.

I think your target and data chart is a good example of white noise. All your groups are generally the same. There's no obvious difference. The velocity data is the same. If you picture a 6" black circle and plot all your data inside that black circle, that's what it would like like in a graph. Generally invisible and falling within acceptable variation. Just some data inside the normal noise of dispersion and variation of generally high quality reloading components and an average shooter. I don't think you always have to shoot a 30rd group to perform load development nor do I think load development is a myth, but your data here would be what someone who argues the opposite would use.

I would load 2 x 10rds of 40.5gr, .020" off the lands, and shoot two groups at 300yds and see what they look like to you. If you are under 1.5" you're probably done. If you're at 1" you're doing good. And you're done.
 
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#31
spife7980 said:
That’s external ballistics, it doesn’t explain internal ballistics and why you are 200 fps faster than others with that amount of powder.
View attachment 8624591
What’s your barrel length?
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Powder is likely dried out. 41gr of H4350 with 140 HYB gets me 2830 out of a 25" barrel. Alpha brass, 450's. He's also really close to the lands which will generate more pressure
 
#32
spife7980 said:
That’s external ballistics, it doesn’t explain internal ballistics and why you are 200 fps faster than others with that amount of powder.
View attachment 8624591
What’s your barrel length?
Click to expand...
I hadn't seen the Berger reloading guide. Interesting that they say the max load with H4350 is 40.7. Hornady says its 41.5 with a 140 bullet. I just checked Hodgdon and they say its even lower at 40.0 with a 140 ELDM. They don't show any data for the Bergers at all.
 
#33
JR1200W3 said:
Powder is likely dried out. 41gr of H4350 with 140 HYB gets me 2830 out of a 25" barrel. Alpha brass, 450's. He's also really close to the lands which will generate more pressure
Click to expand...
That's possible, it is very dry here but we have a whole house humidifier and the powder is stored in the original 8lb jug in a metal cabinet inside the house. The powder is about a year and a half old. I did pick up some additional 1lb containers of 4350 last week, so I will load a few rounds with one of those and see if the results are significantly different between the powder lots.
 
#34
Sooner Sniper said:
That's possible, it is very dry here but we have a whole house humidifier and the powder is stored in the original 8lb jug in a metal cabinet inside the house. The powder is about a year and a half old. I did pick up some additional 1lb containers of 4350 last week, so I will load a few rounds with one of those and see if the results are significantly different between the powder lots.
Click to expand...
I have found that's it's impossible to fight the powder trying to homogenizing with the RH. It will be a constant moving target of velocity until you just let it air out and acclimate. And it's in your favor when it does. You'll get higher velocities and the powder performs well. Some people trying to use humidity packs to try to maintain some 50% moisture content or some such but requires a lot of dicking around and opens you up to another variable that could fail and then have unintended results. I would pour those new 1lb containers into the older jug, leave the lid off for 5 days in an area of your house that isn't being humidified. Having powder with less moisture content is one of the advantages of living in the SW. What you don't want is the opposite. As powder gains moisture it slows down and you'll have to add more powder to your charge and despite being slower velocity you'll still get pressure topping you out. One more reason why I don't want to live in the SE.
 
#35
Sooner Sniper said:
I hadn't seen the Berger reloading guide. Interesting that they say the max load with H4350 is 40.7. Hornady says its 41.5 with a 140 bullet. I just checked Hodgdon and they say its even lower at 40.0 with a 140 ELDM. They don't show any data for the Bergers at all.
Click to expand...
Using my lapua brass I find that the books are usually pretty darn close to where I start having increased bolt lift upon extraction. Most all of my creed h4350 loads are between 37-39.5 grains.
 
#36
I never thought about leaving the lid off to let it acclimate, but that might be why I'm seeing some of the random velocity swings I'm seeing at the same charge weight. The area where I have my powder stored is in the driest part of the house in the unfinished area of our basement. I've never checked the humidity in there, but I'd bet its around 20% or so. I'm gonna order a humidity monitor now. Thx for the advice!
 
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#37
Sooner Sniper said:
I never thought about leaving the lid off to let it acclimate, but that might be why I'm seeing some of the random velocity swings I'm seeing at the same charge weight. The area where I have my powder stored is in the driest part of the house in the unfinished area of our basement. I've never checked the humidity in there, but I'd bet its around 20% or so. I'm gonna order a humidity monitor now. Thx for the advice!
Click to expand...
I just use my Kestrel
 
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