What am I doing wrong

[Kramerica]

I’m having a hard time getting my ES below 25. Single digits would be nice but 15 or below is fine. I’m not shooting benchrest. I use the OCW method for finding my load, while shooting over a chronograph. Generally try to stay at .002-.003 neck tension.

My process
Decap
AMP anneal
Lube hornady one shot
Fl size with Redding type S bushing
Trim, debur, chamfer (as needed, not everytime).
Prime rcbs bench primer
Powder charge RCBS 1500. I have noticed some drift on the scale .1 in both directions.
Seat bullet
Check runout.

 

[Fuj]

Many moons ago, one of my biggest "Ah'Ha' moments was to
work on the uniforming of the primer pockets. I'd also deburr the
flash holes if needed on new brass. Your priming tool can be
consistent in seating depth but some primers may get crunched
too much getting there while some may not be bottomed enough.
I cut my SD's about in half.

 

[rsbhunter]

You might try brushing the inside of the necks with a nylon bore brush before annealing. Also, mandrel the necks, and possibly use a dry lube, graphite or hbn on the inside of necks....I'm guessing your powder charges are as accurate as you can make them ? Just a couple tricks that seem to help...rsbhunter

 

[bfiles]

What kind of brass, how many firings, how are you cleaning it, how are you setting final neck diameter (do you mandrel up after sizing down?), and are you doing anything to lubricate the bullet seating process? One or all of those things will be your answer.

 

[dcali]

If you can, try increasing the charge weight. In my experience, that's what matters most. I've found that you often get a sweet spot where SDs tighten up as you increase charge weight, after which they start going up again. But don't chase SD over good groups. If it shoots, it shoots. SD only matters at long range, and even then, only if it's really bad. (I'm assuming sane ranges, not ELR).

Also, you didn't mention what cartridge you're shooting. Small cases can be very hard to get consistent. Just the nature of the beast.

EDIT: I just read bfiles post below (#6). He's right - I misread your post and thought you were talking about SD. a 25 ES is pretty good. You're done. Load windows tend to be around 30-50 fps wide for the guns I shoot (6 BR, 308 and .223 mostly).

 

[bfiles]

Also, if your ES is 25, your likely SD is down around 7. Check your SD over 20+ rounds and stop worrying if it is below 10. Especially since you aren’t shooting benchrest.

 

[47WillysGuy]

Two things: powder load and firing pin assembly.

Weigh your powder load twice. Make sure you have an accurate load for each case. For me two tenths of spread is to much.

Check your firing pin spring. Does it have worm like curves going down the pin? Replace as needed.

Does the firing pin and spring assembly drag upon insertion? Replace as needed.

A bad spring can cause a firing pin to drag which will affect ES.

May even look at the shroud as a dragging problem.

 

[K22]

How does the load shoot on target?

 

[whatsupdoc]

What caliber?

 

[Coyotefurharvester]

How many shots in your data?

 

[Krogen]

Velocity standard deviation and extreme spread values are meaningless unless referenced to average velocity. Single digit values for a 4000 fps .220 Swift mean one thing while the same numbers on a 1200 fps cast bullet "slowpoke" mean quite another. More useful is coefficient of variation which is simply velocity standard deviation divided by mean velocity. Of course we almost never talk about CV, favoring SD and ES instead. Maybe that's because our chronographs output SD and ES, but not CV.

 

[joshb]

You have to have accurate powder weights to the kernel, if possible and brass sorted to internal volume.

 

[Wayno12]

I’m having a hard time getting my ES below 25. Single digits would be nice but 15 or below is fine. I’m not shooting benchrest. I use the OCW method for finding my load, while shooting over a chronograph. Generally try to stay at .002-.003 neck tension.

My process
Decap
AMP anneal
Lube hornady one shot
Fl size with Redding type S bushing
Trim, debur, chamfer (as needed, not everytime).
Prime rcbs bench primer
Powder charge RCBS 1500. I have noticed some drift on the scale .1 in both directions.
Seat bullet
Check runout.

you need a MUCH better powder measure. If you cant afford an expensive .02 difference scale, then you have to have a sharp are with the balance beam. I used the RCBS for years, wondering the same as you. But what showed up as 43.0 gr Varget on the RCBS varied by +/- half grain or more.
Throw ten loads then go back and beam scale each one .
MAybe

100 x 0.001g Analytical Balance, 1 mg Digital Lab Precision Scale

Responsive Page with Multiple Modules Introduction The USS-DBS46-1 precision balance offers a 100g capacity and 0.001g readability, designed for moderate to high precision applications. It features a strain gauge sensor for reliable results, a backlit LCD for clear readings. This model supports...

ussolid.com

Or find a friend with a really accurate scale and weight those ten, maybe 20 rounds? Youll KNOW why your ES is so far off with the standard auto throw powder dispensers.

I finally bit the bullet and got the V4 scale https://autotrickler.com/pages/autotrickler-v4

 

[LHSmith]

What you are doing wrong?
My guess is if this is for short range you are worrying about chrono numbers and not concentrating on results on target which is the ultimate goal (for me at least).

 

[Ranger188]

A lot more information needed.
Answer some of the questions posted above.
Rifle, setup, caliber, components used, etc..

 

[Ned Ludd]

I'll also jump on the pile...what cartridge??!!!!

This is important information and the question can't really be addressed without it. For example, if it's a .223 Rem, those numbers are totally normal. Don't waste your time trying to reduce them further. If it's a larger cartridge, it will likely be worthwhile trying some of the suggestions mentioned herein.

 

[dusterdave173]

I can get easy low es/sd with some brands brass and then swap and chase it all day long--go back to my favorite brand of brass and bingo. I shoot 223 and PMC brass or Lapua brass and I am golden--every time I try others I chase my rear New brass seems like the worst It has to go a time or two to 'level" out for me I even got a new FX120i thinking I would solve that issue and found out the same brass was better just like before --No matter how accurate I get a load in some brass the numbers stay higher than I can get with others just my two cents worth I am a rookie

 

[One Eye Pete]

Two things: powder load and firing pin assembly.

Weigh your powder load twice. Make sure you have an accurate load for each case. For me two tenths of spread is to much.

Check your firing pin spring. Does it have worm like curves going down the pin? Replace as needed.

Does the firing pin and spring assembly drag upon insertion? Replace as needed.

A bad spring can cause a firing pin to drag which will affect ES.

May even look at the shroud as a dragging problem.

47 WillysGuy hit the nail on the head. Powder charge and the gun itself can cause high ES.
As Eric Cortina said in his video "Precision Reloading is Easy You Complicate It", ES and SD problems are related to Combustion.
Your loading routine contains "check runout" as a final step. In my experience runout as long as it isn't excessive is not a critical factor. However, consistent headspace and bullet seating depth are as they effect case volume. You would be better served by doing quality checks on headspace and seating depth.
The other thing that can cause problems is the case fill ratio. I always try to select a powder that gives me a fill ratio of at least 90+% without a compressed load. Since primers effect combustion they also enter the equation. Primer type and primer seating depth will have an effect.
You don't give enough information to pinpoint the problem but the place to look is at anything that effects combustion, Primer (type and depth), Powder (type & charge), Case Capacity (volume), Neck Tension, Firing Pin & Spring.

 

[Webster]

I’m having a hard time getting my ES below 25. Single digits would be nice but 15 or below is fine. I’m not shooting benchrest. I use the OCW method for finding my load, while shooting over a chronograph. Generally try to stay at .002-.003 neck tension.

My process
Decap
AMP anneal
Lube hornady one shot
Fl size with Redding type S bushing
Trim, debur, chamfer (as needed, not everytime).
Prime rcbs bench primer
Powder charge RCBS 1500. I have noticed some drift on the scale .1 in both directions.
Seat bullet
Check runout.

Try different powders. Gets expensive. You didn't give us the cartridge. Under the title Main Site on the home page, click on your caliber and see what others shoot with great accuracy.

 

[Clancy]

I don’t wanna sound argumentative, but you don’t need any more scale than that to get respectable numbers. If you’re trying to win at Deep Creek, buy the best, but if not…. Use good brass and throughly test your charge weights. ES of 25 for anything but BR is plenty good so long as the gun shoots well.

For what it’s worth, I bought an autotrickler years ago and sold it within 2 weeks. It made absolutely no difference for me. A node is a node.

If anything, I might hunt down a Scott Parker tuned balance beam scale at some point, just in case I’m ever in doubt.