Seeking empirical evidence to support or refute powder/seating-depth nodes

I am new (since 2019) to the long range shooting community and admittedly my experience is limited. I have been frustrated with all the voices claiming their methods are "how it should be done". I am not inferring that their methods don't work, what I am saying is that if so many different methods all produce the same results, accurate loads, then logically not all of the processes in the various methods are as significant as believed. In other words, the methods may work, but not for the reasons we believe. My goal is, through applying the scientific method, to sort out what actually makes a difference in the reloading process and what is just the deeply held dogma of the community.

I deeply appreciate and respect the experience and knowledge of those in this community, and their willingness to share it. I know that their methods work and produce accurate results, all I am trying to do is figure out why. After recently stumbling across the following information, I have radically changed my thoughts on how I approach reloading. I thought the community might benefit from the information they proffer.

I am looking to have an honest discussion about the information linked below and to hear your opinions, many with infinitely more experience and knowledge than I. If you take the time to review either of them, I would welcome your insight, obviously your have been doing this a lot longer than I.


Before anyone can offer suggestions as to the value of this information, we/you need to determine your goals. Do you want a rifle and load that will be used solely for hunting? If so, everything this guy is telling us isn't important. Let's face it, hitting an eight inch circle at ethical hunting distances is achievable without dealing with this level of minutiae. If you want to set a new record in F-class competition, the rabbit hole is very deep.

It's easy to spend a lot of time on systems and procedures that aren't going to move you forward toward your individual goal
 
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I am just glad to know I can save money on components by not wasting my time on seating depth! As you can plainly see seating depth has no bearing on accuracy at all. Since this is just statistically irrelevant.
The ELDM is a hybrid ogive bullet I believe.
 
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I am just glad to know I can save money on components by not wasting my time on seating depth! As you can plainly see seating depth has no bearing on accuracy at all. Since this is just statistically irrelevant.
The ELDM is a hybrid ogive bullet I believe.

My seating-depth ladder looked very similar to yours. My best group was at -0.035" and measured 0.288 MOA (largest group was 0.702 MOA). I loaded 30 identical rounds at -0.035" and shot the ten 3 round groups below at 198 yards (allowing the barrel to cool between groups). Any of the 3 shot groups could have randomly appeared in my seating depth ladder. If any of the groups over 0.3 MOA would have appeared, I would have moved on to another depth. It was PURE RANDOM CHANCE that the 0.288 MOA group ended up in my ladder. I bet if you load up 30 rounds at -0.065" and shoot 10 three shot groups like you did above, you would end up with a similar looking target to the one you have posted. I was shooting a 147 ELDM @2850 fps out of 6.5 PRC.

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My seating-depth ladder looked very similar to yours. My best group was at -0.035" and measured 0.288 MOA (largest group was 0.702 MOA). I loaded 30 identical rounds at -0.035" and shot the ten 3 round groups below at 198 yards (allowing the barrel to cool between groups) below. Any of the 3 shot groups could have randomly appeared in my seating depth ladder. If any of the groups over 0.3 MOA would have appeared, I would have moved on to another depth. It was PURE RANDOM CHANCE that the 0.288 MOA group ended up in my ladder. I bet if you load up 30 rounds at -0.065" and shoot 10 three shot groups like you did above, you would end up with a similar looking target to the one you have posted. I was shooting a 147 ELDM @2850 fps out of 6.5 PRC.

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But what about the -5 tho group? It measures 2.3 inches, so by your rationale this kreiger barrel is only capable of 2.5 MOA no matter what I do? Im a .25 moa shooter and your telling me that if I shoot 30 rounds out of that barrel I will never be capable of keeping it in 1 moa right?
 
Yup, clearly that .381 group was a fluke 🤣
Not a "fluke" but a RANDOM distribution of all the possibilities on the bell curve for his rifle and load. That three shot group could be the closest three points on the bell curve or the farthest three points on the bell curve or anywhere in-between. The only way to know is to shoot a larger sample size.
 
But what about the -5 tho group? It measures 2.3 inches, so by your rationale this kreiger barrel is only capable of 2.5 MOA no matter what I do? Im a .25 moa shooter and your telling me that if I shoot 30 rounds out of that barrel I will never be capable of keeping it in 1 moa right?
No, I would discount that group as things get wonky (science term) when you get that close to the lands. I would love to see you shoot more 3 shot groups with the -0.065" load.
 
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I am just glad to know I can save money on components by not wasting my time on seating depth! As you can plainly see seating depth has no bearing on accuracy at all. Since this is just statistically irrelevant.
The ELDM is a hybrid ogive bullet I believe.
ELD-Ms are secant ogive bullets.

3 shot groups are useless for anything other thaan discarding bad loads. Had you shot all 5 groups at the same BTO it's not unlikely the results would look similar.
 
My seating-depth ladder looked very similar to yours. My best group was at -0.035" and measured 0.288 MOA (largest group was 0.702 MOA). I loaded 30 identical rounds at -0.035" and shot the ten 3 round groups below at 198 yards (allowing the barrel to cool between groups) below. Any of the 3 shot groups could have randomly appeared in my seating depth ladder. If any of the groups over 0.3 MOA would have appeared, I would have moved on to another depth. It was PURE RANDOM CHANCE that the 0.288 MOA group ended up in my ladder. I bet if you load up 30 rounds at -0.065" and shoot 10 three shot groups like you did above, you would end up with a similar looking target to the one you have posted. I was shooting a 147 ELDM @2850 fps out of 6.5 PRC.

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If seating depth makes no difference, next jam some in the lands and some 140 tho off. And they should all be under .5 MOA right? Wont have any that open it up to 1.5 inches?
 
If seating depth makes no difference, next jam some in the lands and some 140 tho off. And they should all be under .5 MOA right? Wont have any that open it up to 1.5 inches?
Why would they all be under .5 MOA? He's not saying that whatsoever.

He did a seating depth test, picked the best one (just like you did) and actually loaded enough to verify how good that depth really was. And with more testing of that specific depth, it proved to just produce a variety of groups, similar to all the groups in the original seating depth test. Proving that it was just a fluke and not some "tuned" depth based off of the 3 shots during testing.
 
If seating depth makes no difference, next jam some in the lands and some 140 tho off. And they should all be under .5 MOA right? Wont have any that open it up to 1.5 inches?
Seating depth absolutely makes a difference when you start getting close to the lands as pressure can spike. It may make a difference in some rifles and with some bullets at reasonable distances off the lands. I am still trying to find that answer for myself. What I have learned for certain is that, for me, making load development decisions on small group sizes (other than discarding bad loads) is a waste of my time and resources, YMMV.
 
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Seating depth absolutely makes a difference when you start getting close to the lands as pressure can spike. It may make a difference in some rifles and with some bullets at reasonable distances off the lands. I am still trying to find that answer for myself. What I have learned for certain is that, for me, making load development decisions on small group sizes (other than discarding bad loads) is a waste of my time and resources, YMMV.
I agree, discarding bad loads is the entire reason anyone ever does load development. That picture I posted is my entire load development! One for power (looking for low SD), and a second for seating depth. Entire load development 30 to 40 rounds unless I have to discard a power or bullet from the combo. Now if you agree that primers and neck tension have some degree of effect on precision and speed consistency. Than congrats you agree with Bench rest competitors that everything matters all the time, its just to what degree you want to chase it. Keeping in mind I have some rifles that will never be capable of better than 2'' no matter what you do.
 
I agree, discarding bad loads is the entire reason anyone ever does load development. That picture I posted is my entire load development! One for power (looking for low SD), and a second for seating depth. Entire load development 30 to 40 rounds unless I have to discard a power or bullet from the combo. Now if you agree that primers and neck tension have some degree of effect on precision and speed consistency. Than congrats you agree with Bench rest competitors that everything matters all the time, its just to what degree you want to chase it. Keeping in mind I have some rifles that will never be capable of better than 2'' no matter what you do.
I have been reloading since the early 90's and have always believed that consistency is the key to accuracy. To this end I have always tried to be meticulous with regards to seating depth, powder charge, neck tension, primers, brass and bullets. Recently I have seen some compelling evidence that challenges my long held belief that small changes in seating depth and powder charge affect accuracy to the degree I previously thought. I am still trying to sort it all out and trying to reproduce, for myself, some of the evidence I have seen from others. If I can achieve the same accuracy at reasonable seating depths (0.020" - 0.050" off the lands) then I can stop fussing with that part of the loading process and focus on other steps that may be more critical to accuracy.
 
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