Seating depth test

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4thefunofit

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A randomized shot order seems to help smooth out extraneous variables. Whether or not it's significant, it still helps with confidence.
 
Longtine88

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I personally would try above the 0.041” in same increments. Like what has been mentioned your getting into another node and I like the second node when I can get to it. Not sure if this is with everyone but I tend to seem to get more consistency with that node than the first node. And generally a deeper seating depth node is generally a wider node is what I’ve found.
 
gohring3006

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If they all are in a half moa, I’d load closest to the lands and that way you won’t have to adjust for throat erosion for while.
 
Mikecr

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Pretty much. .020 or .040 seem to be a decent place to start for powder development. I don’t know that it really matters.
It would matter to me. There is no reason other than pure luck for your initial guess and tweaking only around it, to be the best.
It might have turned out that way, but I would want to know. I would do actual full seating testing, and nowhere near the powder node.

All I see in your abbreviated testing here is coming in and out of powder node -due to seating tweaking (group shaping).
It would do that even if you were in the worst possible seating.
 
Lefty7mmstw

Lefty7mmstw

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It's a 6.5 creed... not really rocket science. I load hornady brass with 143 eld-x and the factory prescribed 41 grains h4350 and a standard rifle primer at factory oal. and my 13 year old dumps 1" groups at 200 so regularly he gets peeved when he pulls one. I have done zero load development and it's a lowly Ruger American wearing a 20x Weaver grand slam scope... I'm a bit low on h4350 so I may flip over to rl17 or I4350, but that's 400 rounds from now so I'm not really caring. The kid's have a 25wssm and a 7rem to putz with too...
 
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Stonyman88

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Curious how others would decipher this. I indicated distance off the lands on each picture, that’s not group size. I felt like I was shooting pretty well today. The only shot that felt off was in target 2 and I noted “pull”. I shot my 4th shot at .026” into the .029” target but the poi was in the same group as the .026, which was my best group of the day. I also noted 1st of the day. From these results I think my seating depth should be .023” which gives me some room as the throat erodes? I wouldn’t be scared of .020” either, especially with that first shot of the day being high, then 3 shots in a small group.

100 yards, 3” spot targets, prone of a bipod and rear bag. Very slight wind right to left. 6.5 creedmoor shooting 147 eldms. Gun is new to me but has 600 rounds through the barrel. Not sure if I worry about throat erosion at this point seeing it’s a 6.5cm and already has 600 rounds down the barrel.View attachment 365047
I guess I would say the 3 third group it came in, then went out after, don't like the vertical groups after that, but not sure what you have written but the last group it came back in , you might try going out a bit more with like 3 more settings after the last one. Also did you work with powder? My 6.5 CM delivers .20 groups with factory Hornady 143 ELD-X, and they are in my CM .060 off . unreal. sure like the last group, always like the ones that are more horizontal. Really nice groups
 
QuietTexan

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This is exactly why seating testing before charge pays dividends
You end up doing both, just like Mike said. You can rough in seating depth before powder, but the depth tuning has to come after powder tuning and needs to be outside of the powder node.
 
gohring3006

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Personally I think you’re overthinking it a little bit.
For the sake of component saving, I’d pick .041 and work with it by first checking velocity numbers with 10 shots or more. If I had those results on a seating test, I would be done with my seating test moving on to velocity and powder tweaking. If you don’t have a refined loading method you can’t blame poor sd and es on powder. You have to have a couple things consistent in your loading technique, like a good scale and neck tension.
 
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Rflshootr

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You end up doing both, just like Mike said. You can rough in seating depth before powder, but the depth tuning has to come after powder tuning and needs to be outside of the powder node.
So let me see if I understand this....you work your powder charge, then intentionally screw it up to tune seating depth and then go back to the best powder charge? Then what? Re-tune the seating depth? What am I missing here?
 
Ucsdryder

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So let me see if I understand this....you work your powder charge, then intentionally screw it up to tune seating depth and then go back to the best powder charge? Then what? Re-tune the seating depth? What am I missing here?
I thought exactly the same thing. It’s a circle. Keep going round and round? If I find a charge it likes and a depth it likes, why would that be the wrong way to do it?
 
QuietTexan

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So let me see if I understand this....you work your powder charge, then intentionally screw it up to tune seating depth and then go back to the best powder charge? Then what? Re-tune the seating depth? What am I missing here?
There's no circle. I shoot the seating depths at 93% of max charge, the odds of that one random charge being the best is pretty low. Shoot a pressure ladder to find the max load for the rifle, shoot a seating depth testing of whatever method, shoot a lot of powder charges at the best seating depth.

Rinse, lather, repeat for anything else you want to change. Why assume your powder choice is the right one that doesn't need to change? I have almost a dozen different powders for my 223, almost that many for 6.5 CMs, at least a half dozen for the big magnums.

And yes, once you find a really good happy load - intentionally try to break it. Load an erratic powder charge and start changing other variables like neck interference, primer seating, different sizing die or something along those lines and you'll see the big nasty groups shift with the variable you're working on. Put a tuner on the barrel and really things move around also.
 
Rflshootr

Rflshootr

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I guess everyone has their own method. I do it a bit differently to try and preserve barrel life and components. Once I find a load that chronos good and consistently shoots acceptably for the intended application, I call it good. If the rifle will shoot 4 or 5 good groups in a row and is consistent within limits every time out, I have no need to chase my tail. At that point, it's time to buy/build a new one and start the process over.
 
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