Home Forums Reloading Big Game Rifles ES, extreme spread,

Today had one load that had an ES of 12, SD of 6,

thats based only on an average of 3 shots, but all other readings today were also only 3 shots,

but with the Es of 12, the vertical on the target was about nil,

So, What factors cause little, or a lot of ES?

Is there a clue here?

.300 wsm with 60 grains of H4350, fps of only 2803,

gave up at 63.5 grains for an fps of 2978, sticky extraction issues.

Would you leave that 175 fps on the table, focus on the 60 grains,

or look for a higher velocity?

group sizes at this point are basically everywhere.

You aren't “giving up” 175 fps, you are over max with your top load right now. I don’t know where a safe maximum load for your rifle is - but definitely below that. An ES of 12 is very low, but can be misleading with only 3 shot strings. Causes include variances in charge weight, charge position in the case, case shape, powder type, primer ignition and barrel condition.

We don’t know what bullet weight you want to use, but H4350 may not be the best powder for top velocity.


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I’m I missing the bullet weight ?

165 grain tsx,

slightly off topic, but they just generally are not that accurate for me.

All charges weighed individually, Remington 9.5 mag primers, new barrel, (about 40 rounds at this point), .050 off the lands, all loads hand checked with Hornady comparator tool.

above was load #1,

2, SD 14, ES 26
3, SD 9, ES 18
4, SD 8, ES 15
5, SD 14,ES 26
6, SD 6, ES 13
7, SD 12, ES 22

all 3 shot averages.

FWIW I have had some very accurate loads with what would be considered high ES and Sd. I usually strive for a velocity and accuracy that is acceptable for the application of the load. They are not necessarily the highest velocity load nor the most consistent.

I’m not real sure what you are asking here ?
I want accuracy and velocity , but i will always take accuracy over velocity. You should be able to find both.
Unless I’m missing something 63.5 grs of H4350 behind a 165 tsx is not over max.
If your not happy try something different ; bullet , weight , powder , etc.
FWIW I’ve found better accuracy , less pressure sighns , and +50-100 FPS with RL 17 over H4350.

Can your provide the charge weights and velocities to go along with the spreads/ES? Otherwise there's no way to make heads or tails of this. With the velocity information you have at least the start of a useful velocity ladder that will allow you to find a node.

SD estimated from 3 shots is next to meaningless.

Mathman has it right. It takes a lot more than 3 shots to get a decent estimate of either standard deviation or range (ES).

I would go even further.
Thinking priorities are totally upside down. Without accuracy, the rest is irrelevant....

Accuracy is an outcome. SD is an indicator. Sticky extraction is more than an indicator--it is a warning.

I use groups of 10 for an SD fix but would defer to Denton or Mathman about the significance level of that--may be just something I read back an eon or two.

I never really pay attention to ES/SD till I have at least 30 shots of a particular load. It only takes one abnormal high and low to completely screw the ES/SD numbers to where you may bypass a very good load just because of a freak happening especially with 3 shots. For load testing I always go 5 shot group for accuracy, velocity and just pay attention to what the target says.

Those numbers have no value from only 3 shots each. They certainly don't mean enough to tell you one load is better than another.
The main value you could get from 3 shot ES numbers is if you found a really large ES, it could be an indication that something is very wrong, but small ES numbers just don't mean much.

As others said, work on accuracy first, forget about ES until you are ready to fine tune a good load.

That makes two of us.

Right after dinner.

Agreed, which is why I mentioned it.

Accuracy is always the main goal, goes with out even saying,
but like I said above, I haven't found the accuracy yet either.

How is the runout? Bedding? Proven scope?