Why high ES??

007hunter

Lil-Rokslider
Joined
Feb 22, 2020
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Curious why I get such high ES? Load was .223 22 grains of X-Terminator with CCI small rifle primer. Shooting 55gr Norma Tipstrike in brand new Norma Match brass. Minimum was 2455 fps and max was 2739 fps. Same load using TAC was better but still 120fps difference.

Is it just a powder thing? Xterm just not great for 223? Or is it something I'm doing?
 

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I had a similar experience with with unreasonable ES. Eventually figured out my powder thrower was the problem.

Throw a bunch of powder and verify it on a separate scale.


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Curious why I get such high ES? Load was .223 22 grains of X-Terminator with CCI small rifle primer. Shooting 55gr Norma Tipstrike in brand new Norma Match brass. Minimum was 2455 fps and max was 2739 fps. Same load using TAC was better but still 120fps difference.

Is it just a powder thing? Xterm just not great for 223? Or is it something I'm doing?
It is going to take a lot more information than that to start identifying potential issues.

1) What powder scale are you using?
2) Case prep method? Same lots?
3) The extremes; are they one or two or a signifiant % of the shots?
 
While there are many variables I start with what Eric Cortina says:

Small groups but high ES - adjust powder charge or change powder.
 
I have a load with 4064 and 55 grain bullets that works fine in long barrels/ bolt gun. But then my M4 has an ES almost 150 ft per second. Incomplete ignition possible due to light bullet, and incomplete burn due to 16 inch barrel. Went to CFE223 and ES is 24.
 
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