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Load development question

Thorough reply that reflects your decades of experience, but can you share at what point you select a powder charge, and how you determine it?
Simple - I look at various reloading manuals and see if they have an accuracy load and start with that powder. Sierra, at least in the past, was spot on most of the time. Lyman and Nosler are also good sources. Sometimes knowledgeable fellow shooters can provide some excellent insights based on their experiences. It's easy to spot the ones that know what they are doing if you observe them and their targets. ;)

In addition, often but not always, a powder that fills the case without having to compress the charge works well. While I have shot some very excellent groups with ball powders, I prefer extruded powders since they seem to be less sensitive to temperature variations. This is important to me because I shoot all year around.

As far as charge, again I keep it simple. I will start a little below the mid-point of published data and work up in 0.5 grain or so depending on case capacity. Keep in mind, I am not striving for competitive bench rest accuracy, just varmint grade (1/2 to 5/8 moa). The published data I prefer is the one developed by the bullet manufacturer. In my experience, this is the most reliable.
 
I have loaded a bunch over the years but, just getting back into precision shooting. When developing the best load for a gun, should you find the most accurate charge and then work on seating depth or, vise versa? If neither of those, what are your suggestions? This will be for both a 223 AR shooting 77gr Bergers and / or SMKs and, a 6BR shooting, most likely, 108gr Bergers.
its a bit of both. sometimes one can run themselves ragged chasing most accurate charge weights when an adjustment to seating depth changes everything.

id recommend dialing them both in as you go. Example: AR is easy, seat to magazine length if thats your feed mechanism. 2.260" is common, but 77s can vary, 2.255" generally feeds better. then charge work-ups and youre set.

6BR; Charge work ups; then seating depth, then revisit charge workups by going a little over and under again, and "see-saw" the two as needed. Temperature plays a part too. i prefer to work up in higher temps to see pressure signs early; if you work-up in the cold; be wary of a summer day at the range.

-Mac
 
Preferred bullet into the rifling .010. If a new cartridge to me, pick the powder that I think will work and shoot a few 2 round groups watching for pressure as I go along. If nothing shows promise move to next powder. Many times revisiting seating depth is not needed, but I do vary it for final testing, just to be sure. Strange things from barrel to barrel do happen from time to time. In a .22BR for example, one barrel loves Varget but the other barrel hates it. If any barrel chambered in .22BR will not shoot AA2015 now you have a serious problem! . Logically thinking, I don't know how you can finalize seating depth if you have the wrong powder to begin with? It seems to be working for some though. Edumicate me? Lol
Paul
 
Do people do the flat spot load development any longer? I prefer finding a consistent powder charge first. 0.2 or 0.3gr increments, find a spot that has similar velocity readings, which impact the target in a similar grouping, load in the middle of the velocity node to start seating tests using the 0.030" Berger method, then fine tune around the best seating depth in either 0.005 or 0.010" steps, then go back to powder to fine tune. The barrel should be calming down by this point and providing tighter SD to get the final load.

I think as long as the final load is tight, it doesn't matter how you get there.
 
Set seating depth at or just touching. Raise powder charge until I see pressure. Start seating depth test in .005" increments. Pressure may drop and I may need to increase powder charge slightly. Two shot groups @200 yds. Just trying to find what doesn't work. May have to change bullets and retest. May have to change bullets again and retest. Once I find a good marriage between the barrel and a bullet then I'll fine tune the powder charge while shooting multiple groups to confirm everything. But it's always bullets/seating depth first. A bad bullet/barrel relationship is just that, bad and no amount of fiddling with the powder will make it shoot.
 
I believe if the powder is a good choice for the combination of bullet/barrel you will see a range where the vertical dispersion is 1 caliber or less with the bullet seated at the recommended coal. Since I'm mainly loading for the field, I don't even test in/near the lands. And if your loading solid copper(lead restrictions) likely you are starting at least 0.025 off touch, with Barnes I seem to find 0.040-0.050 off touch is a better starting point if looking to save components.
 
Just my 20 m$ . . . . I think a lot of us, as "baby handloaders" started out as the load books directed. Start out with lower charges and work up. Then somewhere along the line we learned that you don't have to use LOA's per loading books. We learned that the bullet's relationship to the lands mattered. So we tacked that on as another knob to turn in a search for accurate loads. It seemed like fine tuning. It didn't occur to us that the seating depth might be a better knob than powder charge. Powder charge first stuck as the way to do things. I know I was puzzled when I first heard to find seating depth first. But fortunately, old dogs can indeed learn new tricks.
 
No matter which one you do first, you almost always have to circle back around to it again.
Might be the best advice on this thread. I start with a constant powder charge and adjust seating. Read Bronsons comment again. I do it with 2 shot groups. First 2 go in the same hole. Next dot shot 2 more see if it repeats. If it does, bingo. Now go tomorrow and if it repeats the same way again, I'm ready.Wear your barrel out at matches, not shooting 5 shot groups to look at.
 
From what I have seen there are different powder charge nodes that work . Many variables, and with hybrid bullets different seating depths that work, but they are a function of your chamber. It's easier to change your powder charge than your chamber. So seating depth is dependent on your chamber, start there. An example is the 144gr. Berger. I could not load it at 15 off or there would have been not enough of the bullet in the neck. So I put the bullet where I thought it would work the best, bottom of the bullet at he top of the powder column, all the bearing surface in the neck and came up with an oal 2.855' and .105 jump. It turned out to be exactly where it shot best. And that is where I started. Same with a AR rifle, you don't have many options. Same if you like the bullet with a little jam.
 
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Just my 20 m$ . . . . I think a lot of us, as "baby handloaders" started out as the load books directed. Start out with lower charges and work up. Then somewhere along the line we learned that you don't have to use LOA's per loading books. We learned that the bullet's relationship to the lands mattered. So we tacked that on as another knob to turn in a search for accurate loads. It seemed like fine tuning. It didn't occur to us that the seating depth might be a better knob than powder charge. Powder charge first stuck as the way to do things. I know I was puzzled when I first heard to find seating depth first. But fortunately, old dogs can indeed learn new tricks.
Great comment and I agree with your thought process.
 
Bullet Jump vs Load Density. The interaction of charge weight and seating depth blurs the line for me. I can’t quite get my head around the proverbial Chicken or Egg.

If you are starting load development by focusing on Seating Depth then wouldn’t best method be to adjust powder volume to maintain a consistent load density across the different seating depths. By arbitrarily setting/holding load density constant then the best seating depth (ie Coal) is determined across “normalized” loads. Now with COAL established, the focus turns toward incremental changes to powder volume further refining load density. The target tells you what barrel likes the best.

Am I looking at this wrong?
 
I shot this test on Thursday
AR15, 6x45 with 80gr Nosler BT and H335.
Max charge is 26.2gr, I started at 25gr
With a COAL of 2.330.
H335 wouldn't be my top pick of powders but I had it and figured let's give it a go.
Scored the 80gr balistic tips from classifieds $.35 a piece. Lol
Bottom and top left are same depth bottom is sighter spot 2 clicks right for top and start of test moving in .003 increments.
Seating depth was hammered out in 10 rounds 12 if you count the 2 sighters.
Now that it's shooting small I'll investigate powder in .2 increments.20250417_115551.jpg
By doing seating first it makes reading charge test easier.
Think about it like this...
If your charge and seating are both in a scatter node how can you decipher what your next step is.
Granted some rifles don't like certain bullet powder combinations, and I'm not talking LRBR precision with this test, but I am saying you can grab some random components and put something together that will keep you shooting and for not alot of $$$ invested and still be accurate.
 
I shot this test on Thursday
AR15, 6x45 with 80gr Nosler BT and H335.
Max charge is 26.2gr, I started at 25gr
With a COAL of 2.330.
H335 wouldn't be my top pick of powders but I had it and figured let's give it a go.
Scored the 80gr balistic tips from classifieds $.35 a piece. Lol
Bottom and top left are same depth bottom is sighter spot 2 clicks right for top and start of test moving in .003 increments.
Seating depth was hammered out in 10 rounds 12 if you count the 2 sighters.
Now that it's shooting small I'll investigate powder in .2 increments.View attachment 1653483
By doing seating first it makes reading charge test easier.
Think about it like this...
If your charge and seating are both in a scatter node how can you decipher what your next step is.
Granted some rifles don't like certain bullet powder combinations, and I'm not talking LRBR precision with this test, but I am saying you can grab some random components and put something together that will keep you shooting and for not alot of $$$ invested and still be accurate.
Can’t help but notice you’ve stepped up you’re game with the freezer wrap, the target dots are really uptown from my cheap ass sharpie red +
 
Simply put, one must start somewhere and neither way is correct or incorrect.

Next, if all these test are done from a rest what is there to remove inconsistent operator error? I bet none of these are performed from a fixed machine rest which eliminates any barrel movement..
 

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