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Posted: 2/13/2017 8:26:29 AM EDT
Group Analytics / General Guidance for new Load Developer
5:23 AM
I am trying to figure out the best powder loads for my rifle.  I have read some content online that I found downright confusing; for example the OME method = obhective is not to shoot the tighest groups? Anyone who can explain this would be a huge help, or reloading/load development tips in general.
Other questions:
- What can I learn from:
----Vertical spread?
---- Horizontal Spread?

Special formulas they care to share?
I am running a 6.5 CM:
- Berger Hybrid Target Match 140's
- IMR 4350
- CCI 200 primers
Thus far I have shot about 25 reloads.  I have been using an OCL of 2.8 (per hornady handbook and the length of ELD-M 140's which my gun shoots very well).  My best (highest) groups have been using 40.8-41.5gr of powder (Hornady's max is 41.5gr)

On a side note, once I get the powder load figured out I am going to work on seating depth.  As I said I have been using a OAL of 2.8, but I have a Forster Micrometer Seating Die I am really looking forward to learning how to use.

Thanks
Link Posted: 2/13/2017 9:47:04 AM EDT
[Last Edit: popnfresh] [#1]
When comparing groups I quit looking at extreme spread and go by average to center.
With extreme spread you are only looking at 2 shots which is absolutely pointless.

Extreme spread is only valid for iternet bragging IMO.

Get OnTarget or similar that tells you ATC or mean radius.


Here is a good example. This is clearly a .6moa load but that 10 shot says otherwise. It however is irrelevant and should not be counted in comparing to another load.

Link Posted: 2/15/2017 2:35:28 AM EDT
[#2]
This is a straight forward write up and video of a ladder load development and test. I just wish there was a 300-600yrd range close to us for the testing.
Load development
Link Posted: 2/15/2017 11:51:32 AM EDT
[#3]
That's a very nice write up and good video too.

It should help the OP get a good start on the magic charge range, then he can fine tune seating depth and details.
Link Posted: 2/15/2017 9:45:46 PM EDT
[Last Edit: Happy2shoot] [#4]
I think you (op) mean OCW optimum charge weight. You are looking for the 3 charge weights that have the same shot group center of mass. Pick the middle group charge weight. Now adjust the cartridge overall length to get the smallest group. There is a website.

http://optimalchargeweight.embarqspace.com
Link Posted: 2/15/2017 11:52:32 PM EDT
[#5]
Unfortunately On Target is not an option for me as I am a Mac user.   I looked into the various ways one can run windows on a Mac but it all added up to being rather costly and time consuming for the use of the one program.

I use Ballistic AE (ballistics calc for iphone) which has a Group Analytics feature with functionality similar to On Target but with my hot dog fingers it is kinda a pain in the ass to use.  The info I am hoping to get from this thread is more big picture/conceptual.  For example: when I look at my group from load A and the 3 shots are on the same vertical plane while load B's shots are strung along horizontally what does that tell me about my loads and how can I use that info to get better shooting groups.  Does group A have to much powder? Group B to little of a charge?  Or is it unfortunately not that simple?
Link Posted: 2/16/2017 5:24:57 PM EDT
[#6]
I shoot a ladder test to find a range of charge weights which all result in the same point of impact.  I measure velocity over my chronograph for all rounds fired.

I then load a bunch (20-50 cartridges) at the nominal value for that range.

I shoot at least 20 for group to ensure I am getting good accuracy (small group size).

Honestly, during the ladder testing, I don't worry about wind deflection, just vertical point of impact.  I've adopted that approach because I have never found a load that shoots a tight vertical but not a correspondingly tight horizontal.  

I shoot at 200 yards as the farthest I can see all my shots without needing a second person to operate the targets.  It also means the wind will not cause an unreasonable deflection.
Link Posted: 3/5/2017 12:59:17 PM EDT
[#7]
Download ballisticxlr from http://ballisticxlr.com, fill out the statistics tab and you will see results in quite a number of graphs on the stats and graphs tabs. Free download, free support.
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