Who thinks my scale is jacked?

Stammster

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May 22, 2020
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Houston, Texas
^^^
As I suspected.
Same trend, no shift.
Your scale doesn’t seemed jacked up.
You just have a couple that don’t fit the trend that happened IMO to occur “by chance”, for the possible reasons I speculated earlier.

I load develop similar to you. But for one shot ladders, I’m looking to see how the powder performs with respect to weight vs volume as a trend - in order to identify max and how “hot” that lot is vs published charge/velocity tables (or to calibrate Quickload) . In the case of 1 shot per charge, I weigh every bullet, case, water capacity test, double weigh charges, trim length, CBTO, etc. so that everything is the same as possible. I throw any out that seat with force (I.e. different neck tension.). In reality, I would still expect to see +/- 5-10 fps from what would be an average if you loaded 5 weights the same (aka. ES). This is why I find 1 shot Satterlee ladders often difficult to analysis. However, I guess it is possible to see a flattening trend over 4 charge weights deltas, but never over 2 or even 3. I’m not seeing that anywhere in your set, other than 48.7-49.3...but only when I close one eye and squint real hard. I would put more value in minimal POI changes at 3-4 adjacent points along the ramp.

If I’m looking for nodes of charge weights vs pressure, I’ll shoot 3-5 shot groups and use the average. I’ll throw out any obvious velocity flyers for the reason you have found. In doing so I actually put more value in the SD, ES, and group size anyway. In my experience, analyzing flats spots doesn’t always equal small group size, clustered around a charge weight range - which gives me even more doubt about the 10 shot Satterlee method.

I realize you were short on time, so what you were doing seems logical. Good luck with the rest of your load development.
 
Last edited:

Barrelnut

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Problem seems to go away when you hit about 50.3 Gr. of powder. Since you are using a long case (25-06) maybe you don't have good enough case fill at the lower charges to get good consistent ignition of the powder in the case.
In other words a low powder charge to volume mix.
 

Stammster

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Problem seems to go away when you hit about 50.3 Gr. of powder. Since you are using a long case (25-06) maybe you don't have good enough case fill at the lower charges to get good consistent ignition of the powder in the case.
In other words a low powder charge to volume mix.
I think the OP is using a 257 Roberts AI, not 25-06.
 

sierracharlie338

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Feb 18, 2013
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Texas
Problem seems to go away when you hit about 50.3 Gr. of powder. Since you are using a long case (25-06) maybe you don't have good enough case fill at the lower charges to get good consistent ignition of the powder in the case.
In other words a low powder charge to volume mix.
Cases were definitely not full at the lower charges and the powder fill was much more consistent above 50.

I think the OP is using a 257 Roberts AI, not 25-06.
Correct
 

338 dude

Formerly 'Bill Cauley Jr'
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I’m mainly looking at the huge jump from 49.9 at 2882 FPS to 50.1 at 2943. Seems like a large jump for the .2 grain difference.

Here’s a side note: I shot a three shot group of the 49.9 charge weight and all three shots (according to the magnetospeed) were 30 FPS faster than the 2882 originally posted on trip one. This group was half inch though.

The only exterior variable is trip one was shot around 70 degrees and trip two was around 80 degrees.

No AC running, loaded in the garage, door closed. Yes music but phone was about 5 feet from scale.

So in short, 🤷🏻‍♂️
10° and 30 ft./s may be a little much but I think you have to consider environmental conditions also contributing
 

nksmfamjp

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Jan 5, 2004
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701
When you put your 50 gr check weight on the scale, how does it weigh before each session?

Don’t tell me you aren’t running check weights. IMO, there is no other way to be confident without 10 weighs of a similar check weight to what I’m loading.

 
Last edited:

Starlite

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Dec 8, 2019
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New Brunswick Canada
Am I missing something. Was the powder being used mentioned? In my testing of many powders; and this is no shocker here. The greatest change and differences in velocity is temperature sensitive factors of the powder. As well, what was the humidity of your garage at time of loading. Was there a large difference?
In my opinion all testing should be done at 600Y/M and should be shot in pairs. Also all egos need to be left at home. Truly only pulled shots should be called.
I know this testing part is off topic but deserves to be discussed in all testing

just my 2c
 

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