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What is precision reloading... to you?

2aBaC̶a̶

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Jan 27, 2019
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The term precision reloading is a broad term for a process. My level of precision reloads are different level of precision than the next guy. Got me thinking what are good realistic levels of accuracy for each step of the process for a precision reloader to strive for and what are acceptable? What are the most important and have the greatest effect on es/sd and on target?

I'll go first.

Headspace +/- .002"
Neck tension +/- .001 (pin guages)
Seating pressure - dont measure
Powder weight - CM- .2gn
Primer depth - dont measure
Runout - dont measure
Bullet weight - dont measure
Sorting- dont
 
My means were meager when I first started reloading, so I didn't have all the fancy tools. I actually still don't have all the fancy tools simply because I get (what I consider) "precision" cartridges out of my process. I have a stock Savage 10FP-LE2B in .308 Win and get below .5MOA out to about 500yds and that starts to open up after that. I get about 1MOA at 1000yds, but I am using a 10x fixed power scope, so that could be a factor since it is very hard to replicate point of aim at that distance. I'm looking to upgrade glass to a Vortex with something with an upper end in the 20's for power.

My load is 44.4gr Varget and Federal 210M primers under a 175 SMK in Winchester brass. Bullets seated on the lands. I'm getting about 2750fps.

I think consistency with brass prep, powder charge, and bullet seating are the primary variables that have the biggest effect on accuracy/precision.

Using your list above, here are my answers:

Headspace: +- .002"
Neck tension: don't measure
seating pressure: don't measure
Powder weight - +/- 0.000 gn (every cartridge is dead on)
Primer depth: don't measure
Runout: don't measure
Bullet weight: don't measure, but use high quality bullets (175 SMK's)
Sorting: cases tracked for times fired and same headstamp (usually out of the same lot)

Here is my process for fired brass:

1. Tumble cases
2. Size/de-prime and clean primer pocket (I de-bur flash hole the first time and never thereafter unless I see issues on visual inspection)
3. Trim case and de-bur/chamfer case mouth
4. Prime
5. Powder and bullet

Hope this helps!
 
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The term precision reloading is a broad term for a process. My level of precision reloads are different level of precision than the next guy. Got me thinking what are good realistic levels of accuracy for each step of the process for a precision reloader to strive for and what are acceptable? What are the most important and have the greatest effect on es/sd and on target?

I'll go first.

Headspace -.001" to .0005"
Neck tension -.002" (bushings)
Seating pressure - don't measure
Powder weight - AutoTrickler V3 & V4 (+/-.002gr)
Primer depth - don't measure
Runout - don't measure (Co-Ax press free-float)
Bullet weight - don't measure
Sorting- don't

I try and only have a .0005" variance in all of my measurable processes (read: consistency). For my precision bottle neck cases, I usually don't F.L. size until chambering becomes difficult. I find fire formed cases seem to give me great results with the shoulder bumped back between .001" to .0005". (I always have the rifle in question handy to try sized cases to make sure they chamber easily.)

I find the combination of powder measuring accuracy and neck tension are the 2 things that most greatly influence ES and SD numbers. (Take the environmentals out of this equation.) Being "on target" is the shooter's responsibility.

For straight walled cases, it's a whole different ball game. But I think you're wanting input on bottle neck cases here. I guess I'm a little bit picky....just not as anal as some bench rest guys I know. And in all things in life....your mileage may vary. My way is not the best or only way. It's what works for me.

Andy 6MT
 
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The term precision reloading is a broad term for a process. My level of precision reloads are different level of precision than the next guy. Got me thinking what are good realistic levels of accuracy for each step of the process for a precision reloader to strive for and what are acceptable? What are the most important and have the greatest effect on es/sd and on target?

I'll go first.

Headspace +/- .002"
Neck tension +/- .001 (pin guages)
Seating pressure - dont measure
Powder weight - CM- .2gn
Primer depth - dont measure
Runout - dont measure
Bullet weight - dont measure
Sorting- dont
For me it starts with quality/uniform components, so . . .

Uniform Brass:
Primer Pockets uniformed
Necks turned to uniform thickness
Measurement for case base to shoulder index uniformed to less than .001"
Case length uniformed to less than .001
Cases sorted for volume consistency (minimum to get rid of outliers)
Neck tension consistent
Inside of neck surface with consistent interference for consistent seating resistance

Uniform Bullets:
Buy high priced, high quality, custom bullets that tend to be uniform in every way.
Or . . .
Quality production bullets, sort bullets by COAL or from base of bullet to seating pin contact point to get consistent seating depth.

Primers:
Use quality primers that produce consistent ignition . . . typically match grade.

Powder:
Keep powder consistent by maintaining it's moisture content until it's loaded. As it absorbs moisture from the air its burn rate slows and if it looses moisture to the air the burn rate speeds up.


Seat primers to a consistent depth
Measure powder charges to +/- .02 grs
Seat bullets to a consistent seating depth +/- .005
Check cartridges for TIR less than .002.

Yes, there are different levels of precision it's not a term that's an absolute. But, somewhere there's a line to be drawn where the term precision just shouldn't be applied. 🥴
 
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I think consistency with brass prep, powder charge, and bullet seating are the primary variables that have the biggest effect on accuracy/precision.

Yeah, that seems like a solid foundation (and where I land).

The more detail/consistency you can apply from there the better i suppose...
 
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To some extent, imho runout matters, but the proxy variable is perhaps better summarized by die quality...

Headspace +/- .002"
Neck tension +/- .001 (pin guages)
Seating pressure - dont measure
Powder weight - nearest .1 (.004)
Primer depth - dont measure
Runout - [use good dies]
Bullet weight - dont measure
Sorting- outliers only
 
it means spending time and effort on steps I cant prove have any effect on the target.....but thats not stopping me from doing it ha
 
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My means were meager when I first started reloading, so I didn't have all the fancy tools. I actually still don't have all the fancy tools simply because I get (what I consider) "precision" cartridges out of my process. I have a stock Savage 10FP-LE2B in .308 Win and get below .5MOA out to about 500yds and that starts to open up after that. I get about 1MOA at 1000yds, but I am using a 10x fixed power scope, so that could be a factor since it is very hard to replicate point of aim at that distance. I'm looking to upgrade glass to a Vortex with something with an upper end in the 20's for power.

My load is 44.4gr Varget and Federal 210M primers under a 175 SMK in Winchester brass. Bullets seated on the lands. I'm getting about 2750fps.

I think consistency with brass prep, powder charge, and bullet seating are the primary variables that have the biggest effect on accuracy/precision.

Using your list above, here are my answers:

Headspace: +- .002"
Neck tension: don't measure
seating pressure: don't measure
Powder weight - +/- 0.000 gn (every cartridge is dead on)
Primer depth: don't measure
Runout: don't measure
Bullet weight: don't measure, but use high quality bullets (175 SMK's)
Sorting: cases tracked for times fired and same headstamp (usually out of the same lot)

Here is my process for fired brass:

1. Tumble cases
2. Size/de-prime and clean primer pocket (I de-bur flash hole the first time and never thereafter unless I see issues on visual inspection)
3. Trim case and de-bur/chamfer case mouth
4. Prime
5. Powder and bullet

Hope this helps!
What scale do you use to measure that and do you cut powder kernels to achieve that kind of precision? Just asking because with the extruded powders I use, best I can get is +- .01 without cutting kernels.
 
....as a gasser user, the rounds need to conform to mag limitations, go bang when I pull the trigger and be sufficiently accurate to impact "minute of man" if it comes down to that...preferably at a range beyond whatever caliber they may be using... game animals doesn't shoot back ;)
 
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....as a gasser user, the rounds need to conform to mag limitations, go bang when I pull the trigger and be sufficiently accurate to impact "minute of man" if it comes down to that...preferably at a range beyond whatever caliber they may be using... game animals doesn't shoot back ;)
So progressive press and full send it? That's how I started.
 
What scale do you use to measure that and do you cut powder kernels to achieve that kind of precision? Just asking because with the extruded powders I use, best I can get is +- .01 without cutting kernels.
I made a mistake in my original post. My scale only measures to 0.0 grns, so what I meant was to the tenth of a grain…vice thousandth of a grain. 😁
 
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My process:

1. Tumble brass in rice for ~1 hour
2. Anneal on AMP
3. FL size and de-prime brass - bump shoulders 1-2 thou. Check sizing with either Mituoyo calipers or Whidden case gauge every few cases
4. Trim, chamfer and deburr brass on Giraud
5. Prime on CPS
6. Load up powder with autotrickler w/fx-120i scale. All charges thrown within 0.02 grains of target charge
7. Load projectiles on Forster Co-ax

I don't clean or do anything with primer pockets or flash holes. I don't measure seating force. I don't turn necks. I don't weight sort anything.

The results I achieve are generally SD's of ~5 FPS and 1/3 MOA or better.
 
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