Fps variation, I don't get this

Part of the beauty of handloading is finding what works,and what does not work,loading for the characteristics that suit you.

Powder selection is one of your options.
I began using H-4831 in the 60's when I could buy it from Old Louis for $1.60 a lb,bring my own bleach bottle!!

Its a fine powder FOR ITS APPLICATION.Its made to burn slow with heavy loads. I would ordinarily choose IMR 4350 for both max performance and accuracy in the 30-06 because it is a step quicker.But I am talking over 2700 fps loads.

I used the old surplus 4831 in my 160 gr 7mm Rem mag loads.Zippy ones.
I use it for over 3000 fps loads in my 257 AI.

IMO,you have not selected the best powder for 2200 to 2300 fps 30-06 loads.

I do not have experience pursuing the modest fps accuracy loads you are working with.I do not have Quickload,but it will tell you % of powder burned in the barrel.If you get,for example,a 96 % burn,that 4 % being blown out the muzzle will contribute to inconsistency.

I would suggest stepping to IMR 4895 burn rate.

And you may end up having better results with even quicker powder.

Be careful with quicker powders,but Benchmark might work for you in the velocities you are pursuing.

I do not deny the steps of sorting brass,Lapua brass,etc help,but going to those lengths .IMO.are for when you are trying to reduce your variations to the "Nth degree"

IMO,if you changed nothing else but switching to world class benchrest prepped Lapua weighed,sorted,etc brass,you would see SOME improvement.

But I think if you use W-W brass and find a more optimum powder for your application,you will have far greater gains.

I also noticed the time of your chrono readings.Your chrono detects the passing of the bullet's shadow.

As the sun gets lower on the horizon,the light source/shadow is affected.

I have experienced some weird readings off my chrono toward sundown.
 
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Your load is slightly below Hodgdon's STARTING load. I think you are getting inconsistent ignition of a powder already too slow for the case volume.

I think you should either increase the load, even the Hodgdon MAXIMUM load is at lower than SAAMI maximum pressure; or go to another powder.

If 2200 fps is enough, you would be in good shape around 40 grains of either 4895. Too bad HiVel No 2 is no longer available, that is what they used for the 1930s 300 metre load about that velocity.
 
I've had an Epiphany! !!!!!!!, I can blame my flyers on differences in Brass!!!! .
I knew it couldn't be me shooting all those flyers, hell..:D
 
As others have noted, you are waaaay underpressured/below MINs for that powder: Barely 36,000psi. (assuming H4831)

Run ~58gr (full case, barest/if-any compression)/get to 48,000psi and watch the ignition smooth out.




postscript: 4831 is the best/well-kept secret in the game for Med-Hvy/30-06. One of the very few powders where you can fill the case/darn-near literally can't overload.
 
I advise AGAINST this technique today.H-4831 of the old days was a surplus powder and IT IS NOT THE SAME as newly manufactured H-4831.

With the old powder,you could use quite a bit more than with the new powder.

Don't try this today,but old school,folks might use less sophisticated methods.

Not everyone had scales.Some folks just filled the case of a 30-06 with H4831,seated a bullet,and called it reloading.
 
One of the very few powders where you can fill the case/darn-near literally can't overload.
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I advise AGAINST this technique....
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That was not a technique. That was an observation.
4831 remains once of the safest powders around because it is so forgiving of what would otherwise be terminal stupidity. ;)
 
You are pretty much shooting reduced load from a very slow powder, and it surprises me that it shoots as consistent as it does. As you increase the charge, it should tighten up. Hodgdon lists max charge 60gr (compressed) so keep increasing until it improves, and you hear powder crunching.
 
mehavey,nothing personal intended.

I was trying to back you up with the anecdote about the old time "reloader" getting by with something.
At the same time,I wanted to NOT encourage anyone to try it.

I know that with the old,original surplus H-4831 I did quite well loading 70 gr behind a 160 gr Sierra boat tail in my 7MM Rem mag.With today's New Manufactured H-4831,that would be a dangerous,likely destructive,overload.

So,please understand,my point was not to talk about you.I was saying we can't get away with what used to "work"
 
`Gotcha HiBC... 'never thought it was anything other than
fair warning to those who might take me... "literally" :D ;)
 
I agree with the charge being low and likely is the main issue . I also see this in the OP

every charge was thrown with a lyman auto, +.1/-.0 so I have very little variation.
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I've never used the powder in question but if it's a stick powder even shorter cut . Throwing a charge is not going to be that tight through out all charges . I can get 4320 which is a pretty short cut powder to throw +/- .3gr on the extremes with most being +/- .1gr

My point is if you want to check your ES/SD I recommend weighing each charge .

There's also the issue of how consistent you hold your riffle will effect your ES/SD . I've tested the theory and it is valid . I can dig up the notes and post if anyone wants them .

So , the combination of low powder charge , throwing the charge and inconsistent hold can IMHO easily result in those spreads .
 
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