Precision 6.5 CM - What would you change about my process?

_Thor_ · Sep 30, 2024

Hi all,
I'm a novice reloader and I've been trying to get some handloads for 6.5 CM to be at least as good as the Hornady 140gr ELDM box ammo I shoot. Generally I'm getting SDs around 14-20, ESs around 51-66, but I've been told single digit SDs and ES under 20 is the standard. Here's the rundown of my gear and process:

Using pretty much all once-fired Hornady brass from my ELDM box ammo
I deprime the dirty brass with a Lee depriming die, then lube and size in a RCBS MatchMaster FL die, then tumble in my Frankford Arsenal tumbler with just dish soap. My brass doesn't get very dirty since I shoot on concrete and I'm trying to save the annoyance of collecting steel pins; I've read that sizing brass before cleaning may wear out the dies faster, but again, if it's not filthy is that an issue? Otherwise, would you tumble,size, then tumble again to get rid of the grease?
I prime with a Frankford Arsenal hand primer, which I find is faster than my press' built-in priming widget. Using Remington 9 1/2 LRPs.
I have a Lee perfect powder measure, a trickler and a Hornady digital powder scale. I typically charge the case (H4350) by putting the case on the scale, zeroing it, throw a powder load, and then trickle up to the exact grain of powder that gets the scale to tick over to the correct tenth-grain I want. This is pretty tedious, and I've debated whether just using the powder measure is good enough, regardless of where in the "tenth" it lands.
Then I seat the bullet. I've used almost exclusively Hornady 140 ELDMs. I intend to branch out to others but first I figure my process is the main issue over the projectile selection.

How would you change my process for the best improvement to SD/ES/precision without going absolutely crazy on gear cost? I have some budget, but $700 for powder scales, etc is probably not in the cards for me unless I go all the way into the deep end with this hobby. Some suggestions I've heard from friends are:

Switch to SRP Lapua brass and don't use Hornady brass at all
Experiment more with other projectiles
Get new dies instead of FL dies - I guess neck sizing/shoulder bump is preferable?
Get a case trimmer setup
Get an annealer
Experiment more with seating depth - note, I haven't done much experimentation here at all
Try different primers (LRP)

For these suggestions and any others the forum has, what priority would you put them in?

RegionRat · Sep 30, 2024

That is a lot to unpack, and if I could cure cancer in a few paragraphs I would, but....

The shortest, cheapest learning curve,... comes from getting adopted by a live mentor who has the credentials.

It isn't impossible to learn from books, videos, forums, etc. while on your own. It just takes a whole lot longer and many more rounds on average.

If there is a club/range nearby that shoots the kinds of competition that mirrors the kind of shooting you like, then I would say go there and get adopted by the High Masters and Match Winners.

You will be dogmatically taught what to shoot and what to feed the gun. As time passes, you will also come to understand why they told you what they did. YMMV

abn31c · Sep 30, 2024

Set neck tension with a .262 mandrel
Get Lapua or Peterson brass
Try this and see, might be enough of a fix in these 2 steps.
.02

stello1001 · Sep 30, 2024

Don't change dies to only bump shoulder or only neck size. Full length sizing is good.

Also, just to avoid extra steps, I've full length sized AND decap in one step. Does your die not have a decapping pin? I'd still run a mandrel through it though before charging case and searing bullet.

I'm not sure why you're setting a case on the scale, zero-ing, and then dumping the charge. I'm not saying thats wrong, it's just not something I've ever seen.

Most will drop powder in some type of cup on the scale, then from the cup it goes straight into your case with a funnel.

BuildingConceptsllc · Sep 30, 2024

So, am I understanding you correctly that you are setting an actual primed case on the scale and trickling into it? I wouldn't do it that way for a few reasons. Just use a good cup or shot glass then funnel into your case once the trickle is done. You need something that sits on the scale well so it won't add any fluctuations, but trying to fill a case while on the scale seems pretty difficult anyway.

Better brass will help a lot. Starline is MUCH better than Hornady and pretty good price but lapua is the best and has such a strong support from realoaders for a reason.

I lube with a mix made of 99%alcohol and rcbs lube. You mix it just like the lanolin mixes that are popular and a spray bottle, but rcbs lube is water based. Just some warm slightly soapy water gets it right off in a Tupperware or little bucket and much easier and faster. It's consistent sizing with it too. Just put your cases in a gallon zip lock and spray 3 or 4 times. Close the bag and mix the brass around and then let the alcohol flash off. Happens quickly and works fantastic.

I think those things will help you see more consistent brass, and as a result, lower SD. I found hornady bullets to be inconsistent also, so I only shoot Berger accept in 223, I do shoot Hornady there but I'm not shoot 1000 yds with it either.

Bacarrat · Sep 30, 2024

What powder charges have you tried? 140gr ELDM with H4350 is very forgiving. People are shooting anywhere from 41-42.7gr of powder with good results. Most of my loads with that combo have been under 10SD. 4.2.5gr at 2.805

BuildingConceptsllc · Sep 30, 2024

Bacarrat said:
What powder charges have you tried? 140gr ELDM with H4350 is very forgiving. People are shooting anywhere from 41-42.7gr of powder with good results. Most of my loads with that combo have been under 10SD. 4.2.5gr at 2.805

Yeah that's very close to what I run with a Berger 130otm. 42.65gr of H4350 , and my numbers are very good with it

stello1001 · Sep 30, 2024

BuildingConceptsllc said:
Yeah that's very close to what I run with a Berger 130otm. 42.65gr of H4350 , and my numbers are very good with it

Same here...
42.5 with a 130 AR OTM

My new barrel also liked it and had good numbers but will back it down since it still needs to speed up.

Harman117 · Sep 30, 2024

#1) What's your setup procedure for your Full Length (FL) sizing die? Are you measuring headspace via comparator on once fired brass before and after sizing? Or better yet: testing a sized piece of brass in your gun?

#2) Like others have already mentioned, remove the expander ball or the entire decapping assembly from your FL die and get a dedicated expander die with a few mandrel sizes (.262 and .263 might be all you need)

The videos are an easy to consume example of each point. Should be a good starting point for you.

Edit: Are you chamfering/deburring case mouths before seating? You don't list it out in your procedure so just checking. That's another "cheap" step to do that may help

Baron23 · Sep 30, 2024

Yeah about using more consistent brass like Lapua, Peterson, etc. my friend @GBMaryland really likes Norma brass for consistency.

But in any case, weight sort the brass. Even good brass. Even if it’s the same lot. You will find differences. Sort it into a few widget bands.

And I too don’t get trying to fill a case sitting on a scale. Get a cup made for that and a funnel, IMO.

Harman117 · Sep 30, 2024

Baron23 said:
Yeah about using more consistent brass like Lapua, Peterson, etc. my friend @GBMaryland really likes Norma brass for consistency.

But in any case, weight sort the brass. Even good brass. Even if it’s the same lot. You will find differences. Sort it into a few widget bands.

And I too don’t get trying to fill a case sitting on a scale. Get a cup made for that and a funnel, IMO.

Run an actual test yourself between "weight sorted brass" and non weight sorted brass, all other variables being equal. Make sure to use a large enough sample size to be statistically significant, results will likely surprise you and make you wish you didn't waste time weight sorting brass.

GBMaryland · Sep 30, 2024

I found that Norma made Prime brass had a SD of 4 in my initial work up… 6 SD when the sample size opened up to 50.

45-90 · Sep 30, 2024

I only matters, if it matters.
Depending on how far you're shooting, tight S/D only matter at longer ranges.
Really good groups can be made at short range with fairly high velocity cartridges with fairly large S/Ds.
Quality brass cases is a good start, Lapua, Alpha, are a couple I have used. Inline dies from Wilson can make good ammo, but I don't use mine much as I find it slow.

How much precision do you need to accomplish the task, not what you want...1/2'MOA ammo easily takes care of most needs, but would be horrible 100 yd benchrest ammo.

Bullets, the bullet you like may not be the bullet the barrel likes. So have several brands in that class & weight to try.

Dies? Cheap dies and expensive dies "can" all make good ammo with good brass.

Primers LR or SR no guarantees. I've had larger velocity spreads from Lapua SR Palma brass then their LR, plus the Palma SR was averaging 40 fps less and worse groups. Depending on the powder you choose for your loads, temperature, etc one must test to see the benefits of either.

Powder, your powder weighing description sounds strange...like bringing the case and the charge up to the same weight, regardless of case weight? I wouldn't do that...get some local help.
No matter how careful you weigh powder each kernel contains a different amount of energy, depending on how well the powder is blended, in the chemical mix. It fits into an approximate burn rate...or is scrapped and sold as surplus, or the lot is reblended.
Varget has had some issues in the past...some of it was horrible, velocity issues, accuracy issues, and super large S/ D, especially in one, 1 lb bottle.
Then run 8 lb kegs and it back to consistent.
It takes a whole book to describe what one can do for accuracy... but a lot of that is not needed depending on "your needs", so that's why there are alot opinions. You have to gain general knowledge and experiment for yourself, cause the answers change, and evolve.

AirgunnerPCP · Sep 30, 2024

In my experience the single biggest factor in lowering SDs was switching to a Fx-120i scale. You don't need a whole autotrickler setup; you can still bulk throw powder and trickle up. It's expensive but it will give the biggest gains in consistency.

My process is simple
Optional: Dry tumble only if brass is muddy
1. Lube cases with hornady one shot
2. FL size
3. Dry tumble brass for 30min to remove lube
4. Prime
5. Charge cases using fx120i scale to target weight +-.04gr
6. Seat bullets

This process yields single digit SDs everytime with minimal time at the reloading bench. Unless you're shooting benchrest or Fclass a lot of the extra steps won't give meaningful change in results. There's a lot of dogma surrounding reloading when it really doesn't have to be so complex.

Additionally setting the primed case on the scale then adding powder until your target charge weight is probably not good practice. You run the risk of tolerance stacking the mass of the brass case, primer and powder charge. As stated by previous posters, weigh the charge separately In a consistent container then charge the case.

_Thor_ · Sep 30, 2024

abn31c said:
Set neck tension with a .262 mandrel
Get Lapua or Peterson brass
Try this and see, might be enough of a fix in these 2 steps.
.02

I don't think I understand the difference between a mandrel and a bushing. My RCBS Matchmaster FL die set takes bushings and if memory serves I used a .288 bushing. It also has a copper piece inside attached to the decapping pin - is that a mandrel? I'm not sure if that's a swappable piece or if I'm completely off there to be honest.

stello1001 said:
Don't change dies to only bump shoulder or only neck size. Full length sizing is good.

Also, just to avoid extra steps, I've full length sized AND decap in one step. Does your die not have a decapping pin? I'd still run a mandrel through it though before charging case and searing bullet.

I'm not sure why you're setting a case on the scale, zero-ing, and then dumping the charge. I'm not saying thats wrong, it's just not something I've ever seen.

Most will drop powder in some type of cup on the scale, then from the cup it goes straight into your case with a funnel.

It does have a decapping pin. I think I ended up with the separate decapping die because at one point I was depriming, then washing, then sizing, then washing again. I guess there's no reason to have separates steps for that.

BuildingConceptsllc said:
So, am I understanding you correctly that you are setting an actual primed case on the scale and trickling into it? I wouldn't do it that way for a few reasons. Just use a good cup or shot glass then funnel into your case once the trickle is done. You need something that sits on the scale well so it won't add any fluctuations, but trying to fill a case while on the scale seems pretty difficult anyway.

Better brass will help a lot. Starline is MUCH better than Hornady and pretty good price but lapua is the best and has such a strong support from realoaders for a reason.

I lube with a mix made of 99%alcohol and rcbs lube. You mix it just like the lanolin mixes that are popular and a spray bottle, but rcbs lube is water based. Just some warm slightly soapy water gets it right off in a Tupperware or little bucket and much easier and faster. It's consistent sizing with it too. Just put your cases in a gallon zip lock and spray 3 or 4 times. Close the bag and mix the brass around and then let the alcohol flash off. Happens quickly and works fantastic.

I think those things will help you see more consistent brass, and as a result, lower SD. I found hornady bullets to be inconsistent also, so I only shoot Berger accept in 223, I do shoot Hornady there but I'm not shoot 1000 yds with it either.

Yes, I am trickling the last tenth or two directly into the case on the scale. I agree it's not ideal. I think I just had issues before using a funnel where I'd lose a few particles of powder while funneling because the funnel's larger diameter around the case neck left a ridge where the powder could get trapped and not go in. I might just be overthinking it.

I'll definitely give the alcohol/lube method a try; that sounds like a really clean way to get the case prep done. As for the bullets, I've seen lots of people favor the Berger LRHTs; I see 144 and 153 grain available in 6.5 but I'm not really sure what the tradeoffs between the would be unless there's a perceptible different in wind performance or recoil.

stello1001 · Sep 30, 2024

_Thor_ said:
I don't think I understand the difference between a mandrel and a bushing. My RCBS Matchmaster FL die set takes bushings and if memory serves I used a .288 bushing. It also has a copper piece inside attached to the decapping pin - is that a mandrel? I'm not sure if that's a swappable piece or if I'm completely off there to be honest.

It does have a decapping pin. I think I ended up with the separate decapping die because at one point I was depriming, then washing, then sizing, then washing again. I guess there's no reason to have separates steps for that.

Yes, I am trickling the last tenth or two directly into the case on the scale. I agree it's not ideal. I think I just had issues before using a funnel where I'd lose a few particles of powder while funneling because the funnel's larger diameter around the case neck left a ridge where the powder could get trapped and not go in. I might just be overthinking it.

I'll definitely give the alcohol/lube method a try; that sounds like a really clean way to get the case prep done. As for the bullets, I've seen lots of people favor the Berger LRHTs; I see 144 and 153 grain available in 6.5 but I'm not really sure what the tradeoffs between the would be unless there's a perceptible different in wind performance or recoil.

MKM makes a decent budget friendly funnel. They are appropriate to the caliber you select so it is a good fit and no powder will fall out.

The bushing is a donut. At least we can think of it as such. They make then in different sizes. Your brass, the neck part of it, will go into this donut and gets squeezed to become smaller. You're essentially sizing the neck by squeezing in the outside diameter.

The mandrel is a cylinder. This sizes the neck by sliding in and out of it and pushes out the inside diameter. You have to size the neck smaller first, so you can then drag a mandrel out and open up the neck with said mandrel. If the inside neck diameter is too large and mandrel fits loosely its obviously not doing anything. That's why you can use a regular die that sizes the neck or a bushing die that sizes the neck down enough for you to get a mandrel to do the final sizing.

I haven't looked up your specific dies to know what you have. But I'll have to assume that your die has a decapping pin with an expander ball. The expander ball is an egg shaped figure that does what a mandrel is supposed to do. It opens the neck back up.

However, many prefer the mandrel over the expander ball. The ball is only in contact with the case neck very little at a time because of its geometry. Most will remove the decapping pin with expander as they just want to use the die body to size the case body without sizing the neck. Then, a mandrel is used to get the final sizing of the neck that's desired. You would obviously have to decap at some point so that's 3 operations.

I tried using a die with the decapping pin and expander ball to both decap and size the case body. Then I still ran the mandrel because I believe the mandrel could size the neck more uniformly. Many will probably say I should just do the 3 steps and quit being lazy by trying to eliminate one step. However, I had pretty good results with my experiment and it saves me time.

_Thor_ · Sep 30, 2024

Bacarrat said:
What powder charges have you tried? 140gr ELDM with H4350 is very forgiving. People are shooting anywhere from 41-42.7gr of powder with good results. Most of my loads with that combo have been under 10SD. 4.2.5gr at 2.805

I've only used H4350. I've worked my way up from 40.0 up to 41.0, and now testing 41.5 - 41.7 gr. I was trying to get velocities matching box ELDM but have just switched barrels and now find that I need to up the charge further to get those same velocities. Does "forgiving" mean that I won't net much precision by measuring more precisely with this powder, but others might differ?

Harman117 said:
#1) What's your setup procedure for your Full Length (FL) sizing die? Are you measuring headspace via comparator on once fired brass before and after sizing? Or better yet: testing a sized piece of brass in your gun?

#2) Like others have already mentioned, remove the expander ball or the entire decapping assembly from your FL die and get a dedicated expander die with a few mandrel sizes (.262 and .263 might be all you need)

The videos are an easy to consume example of each point. Should be a good starting point for you.

Edit: Are you chamfering/deburring case mouths before seating? You don't list it out in your procedure so just checking. That's another "cheap" step to do that may help

I haven't done any of what you mentioned and this is all great info. I need to get a comparator set for sure and measure as you've described. My setup was the basic RCBS "how to setup" instructions, aka threading in the die to the shell holder + 1/8 or 1/4 turn extra.

I'm unclear on the suggestion about the suggestion about getting a separate expander die - is that to replace my existing sizing die, or would you FL resize(minus expander ball), then use this new expander die with a mandrel? Would this be the type of expander die you'd recommend?

I'm not chamfering or deburring. Are you talking about something like this? Also, I'm assuming that's separate from case trimming, correct?

45-90 said:
I only matters, if it matters.
Depending on how far you're shooting, tight S/D only matter at longer ranges.
Really good groups can be made at short range with fairly high velocity cartridges with fairly large S/Ds.
Quality brass cases is a good start, Lapua, Alpha, are a couple I have used. Inline dies from Wilson can make good ammo, but I don't use mine much as I find it slow.

How much precision do you need to accomplish the task, not what you want...1/2'MOA ammo easily takes care of most needs, but would be horrible 100 yd benchrest ammo.

Bullets, the bullet you like may not be the bullet the barrel likes. So have several brands in that class & weight to try.

Dies? Cheap dies and expensive dies "can" all make good ammo with good brass.

Primers LR or SR no guarantees. I've had larger velocity spreads from Lapua SR Palma brass then their LR, plus the Palma SR was averaging 40 fps less and worse groups. Depending on the powder you choose for your loads, temperature, etc one must test to see the benefits of either.

Powder, your powder weighing description sounds strange...like bringing the case and the charge up to the same weight, regardless of case weight? I wouldn't do that...get some local help.
No matter how careful you weigh powder each kernel contains a different amount of energy, depending on how well the powder is blended, in the chemical mix. It fits into an approximate burn rate...or is scrapped and sold as surplus, or the lot is reblended.
Varget has had some issues in the past...some of it was horrible, velocity issues, accuracy issues, and super large S/ D, especially in one, 1 lb bottle.
Then run 8 lb kegs and it back to consistent.
It takes a whole book to describe what one can do for accuracy... but a lot of that is not needed depending on "your needs", so that's why there are alot opinions. You have to gain general knowledge and experiment for yourself, cause the answers change, and evolve.

I'm shooting PRS-style matches between 400-1300 yards, for reference. I think 1/2 MOA would certainly be sufficient. I'll look into getting some Lapua or Alpha brass for sure.

To be clear though, I'm not bringing the case+charge weight up to a uniform total weight! What I am doing is taring the scale with the empty primed case on it (to 0.0 gr), then adding powder until I reach desired charge via throwing+trickling. Someone else mentioned tolerance stacking, but I think that is maybe a misunderstanding of my odd weighing process. Since I'm zeroing the scale WITH the case on it and then adding just the desired weight of powder, I don't think I'm adding additional error into the measure, unless the scale is less accurate at higher gross weights maybe, but someone could correct me. Regardless, it sounds like it's much more standard to just use a funnel, so I'll likely transition to doing that instead.

_Thor_ · Sep 30, 2024

stello1001 said:
MKM makes a decent budget friendly funnel. They are appropriate to the caliber you select so it is a good fit and no powder will fall out.

The bushing is a donut. At least we can think of it as such. They make then in different sizes. Your brass, the neck part of it, will go into this donut and gets squeezed to become smaller. You're essentially sizing the neck by squeezing in the outside diameter.

The mandrel is a cylinder. This sizes the neck by sliding in and out of it and pushes out the inside diameter. You have to size the neck smaller first, so you can then drag a mandrel out and open up the neck with said mandrel. If the inside neck diameter is too large and mandrel fits loosely its obviously not doing anything. That's why you can use a regular die that sizes the neck or a bushing die that sizes the neck down enough for you to get a mandrel to do the final sizing.

I haven't looked up your specific dies to know what you have. But I'll have to assume that your die has a decapping pin with an expander ball. The expander ball is an egg shaped figure that does what a mandrel is supposed to do. It opens the neck back up.

However, many prefer the mandrel over the expander ball. The ball is only in contact with the case neck very little at a time because of its geometry. Most will remove the decapping pin with expander as they just want to use the die body to size the case body without sizing the neck. Then, a mandrel is used to get the final sizing of the neck that's desired. You would obviously have to decap at some point so that's 3 operations.

I tried using a die with the decapping pin and expander ball to both decap and size the case body. Then I still ran the mandrel because I believe the mandrel could size the neck more uniformly. Many will probably say I should just do the 3 steps and quit being lazy by trying to eliminate one step. However, I had pretty good results with my experiment and it saves me time.

I see, thanks for the information. Looking into it more, my RCBS Matchmaster does indeed have an expander ball. It sounds like the consensus is to get an additional expander die and some mandrels. I believe most dies/presses are cross-compatible, are they not? So I don't necessarily have to stick with RCBS brand dies if there's a better one out there.

GBMaryland · Sep 30, 2024

I tend to cheat with initial workups for loads:

I find a factory round that seems to shoot quarter to half MOA at 100 yards, and then I duplicate that load from a velocity standpoint.

I’m typically concerned about how accurate something is out to 1000 yards.

Using that process has not failed me yet.

The only process in recent history that I had to work a load up for was using Warner tool company 180 grain solid copper bullets for my 300 win mag.

JerkyFreak · Sep 30, 2024

The easy route is to use blue box brass with yellow box bullets out of a good barrel.

Difficult to get it wrong with that combination.

RegionRat · Sep 30, 2024

_Thor_ said:
I believe most dies/presses are cross-compatible, are they not?

Affirmative. Unless you go out of your way to look for really big stuff, the vast majority of the presses and dies you find will be 7/8"-14

stello1001 · Sep 30, 2024

_Thor_ said:
I see, thanks for the information. Looking into it more, my RCBS Matchmaster does indeed have an expander ball. It sounds like the consensus is to get an additional expander die and some mandrels. I believe most dies/presses are cross-compatible, are they not? So I don't necessarily have to stick with RCBS brand dies if there's a better one out there.

That is correct. Most dies will work in most presses. If it is of a different thread pitch or size or different type, it will most likely state it.

What I did, is I measured the outside diameter on the neck of a fired case. It's the brass I will be using as I have many from the same lot and it is good brand brass. With that measurement, I went to forster website and bought some of their dies. They will hone the dies for you to a custom dimension. I took my fired measurement and subtracted 4 thousands.

Normally, you'll want to size your fired brass 3 to 5 thousands under fired outside neck diameter and then expand half a thousandth to maybe 2 to 3 thousands under bullet diameter.

45-90 · Sep 30, 2024

_Thor_ said:
I've only used H4350. I've worked my way up from 40.0 up to 41.0, and now testing 41.5 - 41.7 gr. I was trying to get velocities matching box ELDM but have just switched barrels and now find that I need to up the charge further to get those same velocities. Does "forgiving" mean that I won't net much precision by measuring more precisely with this powder, but others might differ?

I haven't done any of what you mentioned and this is all great info. I need to get a comparator set for sure and measure as you've described. My setup was the basic RCBS "how to setup" instructions, aka threading in the die to the shell holder + 1/8 or 1/4 turn extra.

I'm unclear on the suggestion about the suggestion about getting a separate expander die - is that to replace my existing sizing die, or would you FL resize(minus expander ball), then use this new expander die with a mandrel? Would this be the type of expander die you'd recommend?

I'm not chamfering or deburring. Are you talking about something like this? Also, I'm assuming that's separate from case trimming, correct?

I'm shooting PRS-style matches between 400-1300 yards, for reference. I think 1/2 MOA would certainly be sufficient. I'll look into getting some Lapua or Alpha brass for sure.

To be clear though, I'm not bringing the case+charge weight up to a uniform total weight! What I am doing is taring the scale with the empty primed case on it (to 0.0 gr), then adding powder until I reach desired charge via throwing+trickling. Someone else mentioned tolerance stacking, but I think that is maybe a misunderstanding of my odd weighing process. Since I'm zeroing the scale WITH the case on it and then adding just the desired weight of powder, I don't think I'm adding additional error into the measure, unless the scale is less accurate at higher gross weights maybe, but someone could correct me. Regardless, it sounds like it's much more standard to just use a funnel, so I'll likely transition to doing that instead.

Thanks for clearing that up...Most everyone uses the powder pan, cause it's the SAME weight, and variables do stack up, and strain gauge calibration is most likely not linear in the purest form. The case a bit heavy but not enough to move up the digital scale, then adding the powder a fraction light could bring the digital reading to where it appears perfect but is in fact not.

Bacarrat · Sep 30, 2024

Hornady use to put the load data on their ammo. It was 41.5gr of H4350 with the 140s The components you have should be good enough to get some decent SDs. Hornady brass while not optimal, can produce good results. Powder charge IMO should be able to get you there. Dies, annealing ect will not get you as much change as the charge. Shit, I use 2 different brass brands (Lapua and Prime) with the exact same loads and they shoot exactly the same.

_Thor_ said:
I've only used H4350. I've worked my way up from 40.0 up to 41.0, and now testing 41.5 - 41.7 gr. I was trying to get velocities matching box ELDM but have just switched barrels and now find that I need to up the charge further to get those same velocities. Does "forgiving" mean that I won't net much precision by measuring more precisely with this powder, but others might differ?

45-90 · Sep 30, 2024

Something I used to do many yrs ago was load all the 308 long range 800 to 1400 yds ammo on a Dillon progressive, with thrown charges using a modified rotary drum, with consistent rhythm when running the press, I got single digit S/D s on the old chronograph, when checked..and not very often.
Sometimes only check 100 yd group and velocity at 100 yds every 1000 rds.
At 1000 yds your target tells you how consistent the ammo and the shooter are doing.
Through barrel after barrel very few rds were fired under 800 yds.
I used Lapua brass, Fed match primers, Varget, and many thousands of 155 Lapua, at max loads where powder burns well, thrown charges, loaded on the Dillon progressive, and I wasn't the only one.
That's why I say, if it doesn't mater, it doesn't matter, once you reached the 1/2" goal, go shooting, and quit wasting the barrel testing, and time with intricate reloading practices....go out and shoot, be observant, practice with purpose, alway feel the wind, learn the air currents, own your area, get mentally into the wind and the rifle, which becomes the extension of your concentrated focus.
It ain't the reloading.... once "reasonable" accuracy is attained with your loads.

HMRamateur · Oct 1, 2024

If you are decapping before sizing, and your sizing die takes bushings, forget the mandrel. Try different bushings first. I have not noticed a difference with a properly sized bushing and with a mandrel. They're just 2 different tools to accomplish the same job. I won't get into the argument over the difference in concentricity of the inside of the case mouth between the two, as it has very little effect with reloading for the majority of people's needs.

I prefer the mandrel over the decapping rod/button that is in a non bushing sizing die though. Pulling the button through the mouth of the brass stretches the brass and will require more trimming, rather than pushing the mandrel into the case. I see very little change in case length this way. Using a bushing will negate the need to open the mouth back up.

When it comes to cleaning before sizing, it isn't just dirt from the brass hitting the ground that gets the die gunked up, it's the carbon residue from the little explosion happening in it. If you don't clean your brass first, make sure you clean your die a lot, the last thing you want is a stuck case in the die.

Make sure you are setting your FL die up properly to bump the shoulder a minimal amount. There are some good videos on YouTube showing how to achieve proper headspace from shoulder bumping brass with a FL sizing die.

WilburW · Oct 1, 2024

I’ve been through exactly what you are going through with 6.5CM and H4350.
The first significant improvement was from changing away from Hornady brass to Lapua.
Next, I never got great results with ELD projectiles. My groups shrunk dramatically with others, especially Berger’s.
You will get greater consistency with a better powder measure system. I ended up using an RCBS Chargemaster for a few years and it brought greater results yet was easy to use.
The H4350 is a great powder for 6.5CM. If you decide to stay with that powder, you should be fine. Many reloaders end up in the 41(ish) grains of powder range for the 140 grain class bullet.
You are on the right track.
It can turn into a very deep and expensive rabbit hole should you decide to keep chasing better and better results.
However, you are very close to reaching a level of results that is very satisfying and reproducible!

GBMaryland · Oct 1, 2024

Well, to put this entire page into a one liner:

Consistency in you process is what provides accuracy.

Harman117 · Oct 1, 2024

_Thor_ said:
I haven't done any of what you mentioned and this is all great info. I need to get a comparator set for sure and measure as you've described. My setup was the basic RCBS "how to setup" instructions, aka threading in the die to the shell holder + 1/8 or 1/4 turn extra.

I'm unclear on the suggestion about the suggestion about getting a separate expander die - is that to replace my existing sizing die, or would you FL resize(minus expander ball), then use this new expander die with a mandrel? Would this be the type of expander die you'd recommend?

I'm not chamfering or deburring. Are you talking about something like this? Also, I'm assuming that's separate from case trimming, correct?

#1) Following the basic "How to setup" FL instructions aka thread the die to the shell holder +1/8 to 1/4 turn often oversizes the brass (too much work being done) which can even lead to case head separation. Hornady makes a Headspace Comparator set for low $ that works with most calipers (assuming you have those). Watch the first video a few times and start setting your FL die appropriately to YOUR rifle using the method described.

#2) Yes, I could see how it's confusing, a lot of different people talking at once to you. You want both a FL die (remove the expander ball) and a Mandrel Expander die. Think of it in this high-level way: the FL die sizes the outside of the brass by "squeezing it" down to size, then the expander mandrel will expand the inside of the neck/case mouth out to almost the bullet diameter. Just watch the second video a few times and it will be clear. I'd recommend the 21st century expander die (with viewing window) and their mandrels. 0.263" (0.001" under bullet diameter) and 0.262" (0.002" under bullet diameter) these mandrels will be enough to start.

#3) You should also be chamfer/deburring every time whether you trimmed the case to length or not. You don't want to remove a lot of material doing this, the goal is to eliminate sharp edges/burrs. Some expensive trimmers will actually trim, chamfer and deburr in one step, but they're $$$. You can go the powered route, but a nice hand tool will also work and be much lower cost. A lot of people make chamfer/deburring tools, I'd recommend one that is a VLD profile.

You do those 3 steps and your ammo will improve drastically, without dropping a ton of coin.

Slides · Oct 1, 2024

I don't think brass or prep is your easiest win. Yes Lapua, Paterson, Alpha or Norma brass is more consistent but finishing loads on an FX scale or trickling up on a mechanical balance will be significantly more consistent than cheap digital scales even with your Hornady brass. You don't need to finish the load into the case either, finish in a pan and tip in.

tomanyguns · Oct 12, 2024

There’s one thing I haven’t seen mentioned. Is your Hornady brass all one lot? Whatever brass your using, single lots have more to do with low SD’s than anything. Hornady makes better brass than people give it credit for. Use single lots and that helps immensely.

I’ve also shot tons of ELD-M’s with single digit SD’s. That’s not the issue. Neither is neck tension and all the other stuff people are suggesting (although having neck tension around 2-thousandths seems to give best results) Single lots of every component is first. Consistency in your loading is next. A charge that is as close to exact is the final piece. A simple balance beam scale would work better than an inexpensive digital scale. I used to use an RCBS 505 scale and could regularly make ammo with Single digit SD’s. Make sure every charge is identical…

45-90 · Oct 13, 2024

Low S/D are not hard to obtain, with most bottle neck cartridges. Even autoloaders can get there and have accurate ammunition.
Good quality brass and a lapped match barrel is a good start, but military LC brass can do the job with bullets the barrel likes. Try different bullets, seating up close to the lands usually helps, but long jumps can be surprisingly very accurate too, but less often.

Large primer or small primer, after using both for many years, I lean toward LR as being more consistent, cause it handles the variations of temperature and different powders better, across the board.
In one small test the small rifle primer VS large rifle primer, the SR had less accuracy, higher S/D and lost 40 fps with everything else the same.
Although I've used them to shoot some small groups in the warm weather, today I lean toward LR primer.
I use a variety of dies, all will produce accurate ammo, I like Wilson FL bushing die the best, it just decaps, FL sizes, & bumps the shoulder back, but does not have an expander ball, the bushing sizes the neck to the appropriate size, for the brass used.
I machine my own bushings so I get the neck tension I desire with the different brass cases, and machine gauge pins to check the inside diameter of the case mouth.
Powder, H 4350 is a standard good accuracy, low SD powder for the 6.5 CM.
Ya didn't say what you're shooting it in.
Barrel quality can make a big difference.

_Thor_ · Oct 14, 2024

tomanyguns said:
There’s one thing I haven’t seen mentioned. Is your Hornady brass all one lot? Whatever brass your using, single lots have more to do with low SD’s than anything. Hornady makes better brass than people give it credit for. Use single lots and that helps immensely.

I’ve also shot tons of ELD-M’s with single digit SD’s. That’s not the issue. Neither is neck tension and all the other stuff people are suggesting (although having neck tension around 2-thousandths seems to give best results) Single lots of every component is first. Consistency in your loading is next. A charge that is as close to exact is the final piece. A simple balance beam scale would work better than an inexpensive digital scale. I used to use an RCBS 505 scale and could regularly make ammo with Single digit SD’s. Make sure every charge is identical…

My powder/primers/bullets are generally same lot for any batch I'm doing, though the brass is very likely not as it's mixed up brass I've processed in batches. I would hope the hornady digital scale I have is accurate enough that I don't need to upgrade immediately - I believe I'm using the Hornady G3-1500. I've bought some Lapua brass so hopefully I'll get some better results as this will obviously be from a single batch, but also better brass.

45-90 said:
Low S/D are not hard to obtain, with most bottle neck cartridges. Even autoloaders can get there and have accurate ammunition.
Good quality brass and a lapped match barrel is a good start, but military LC brass can do the job with bullets the barrel likes. Try different bullets, seating up close to the lands usually helps, but long jumps can be surprisingly very accurate too, but less often.

Large primer or small primer, after using both for many years, I lean toward LR as being more consistent, cause it handles the variations of temperature and different powders better, across the board.
In one small test the small rifle primer VS large rifle primer, the SR had less accuracy, higher S/D and lost 40 fps with everything else the same.
Although I've used them to shoot some small groups in the warm weather, today I lean toward LR primer.
I use a variety of dies, all will produce accurate ammo, I like Wilson FL bushing die the best, it just decaps, FL sizes, & bumps the shoulder back, but does not have an expander ball, the bushing sizes the neck to the appropriate size, for the brass used.
I machine my own bushings so I get the neck tension I desire with the different brass cases, and machine gauge pins to check the inside diameter of the case mouth.
Powder, H 4350 is a standard good accuracy, low SD powder for the 6.5 CM.
Ya didn't say what you're shooting it in.
Barrel quality can make a big difference.

I'm shooting this in a Tikka, recently rebarreled with a 26" Proof Match Contour Steel barrel. Besides the lapua brass I'm about to try, I've also grabbed some 144 Berger LRHTs and Barnes match burners to try. I am sticking with LRP right now because I have a fair number of those, more than SRPs.

Harman117 · Oct 15, 2024

Keep us updated and let us know your results! Interested in the path you end up taking and the direct impact it has

Seymour Fish · Oct 15, 2024

45-90 said:
Low S/D are not hard to obtain, with most bottle neck cartridges. Even autoloaders can get there and have accurate ammunition.
Good quality brass and a lapped match barrel is a good start, but military LC brass can do the job with bullets the barrel likes. Try different bullets, seating up close to the lands usually helps, but long jumps can be surprisingly very accurate too, but less often.

Large primer or small primer, after using both for many years, I lean toward LR as being more consistent, cause it handles the variations of temperature and different powders better, across the board.
In one small test the small rifle primer VS large rifle primer, the SR had less accuracy, higher S/D and lost 40 fps with everything else the same.
Although I've used them to shoot some small groups in the warm weather, today I lean toward LR primer.
I use a variety of dies, all will produce accurate ammo, I like Wilson FL bushing die the best, it just decaps, FL sizes, & bumps the shoulder back, but does not have an expander ball, the bushing sizes the neck to the appropriate size, for the brass used.
I machine my own bushings so I get the neck tension I desire with the different brass cases, and machine gauge pins to check the inside diameter of the case mouth.
Powder, H 4350 is a standard good accuracy, low SD powder for the 6.5 CM.
Ya didn't say what you're shooting it in.
Barrel quality can make a big difference.

Using h4350 is the easy button. 270’ 140 Berger vld, ancient mixed fed brass, fed 210m, seating .012” off at random, ladder from 50 gr to 53 gr in .5 gr increments went in a ragged hole .75” at 100. The 53.0 felt and sounded best. This is perhaps a key often overlooked. The 53.0 shit .205” with anES of Zero. 2970 across 5 shots. No rest or bipod, just some crap bags. The hold included hard pull to shoulder and firm grip on forend, a hunting hold for an 8 lb rifle. Quality 30 yr old 24” bbl. Nodes across 3 grains of powder indicate to me the right powder is happy with the right primer. Zero ES puts the exclamation point on this notion. Due to the placement of the 53.0 shot at the top of this ragged group, some positive compensation may exist. Powder was weighed to the kernel. Good stopping point.

Harman117 · Oct 15, 2024

Seymour Fish said:
Using h4350 is the easy button. 270’ 140 Berger vld, ancient mixed fed brass, fed 210m, seating .012” off at random, ladder from 50 gr to 53 gr in .5 gr increments went in a ragged hole .75” at 100. The 53.0 felt and sounded best. This is perhaps a key often overlooked. The 53.0 shit .205” with anES of Zero. 2970 across 5 shots. No rest or bipod, just some crap bags. The hold included hard pull to shoulder and firm grip on forend, a hunting hold for an 8 lb rifle. Quality 30 yr old 24” bbl. Nodes across 3 grains of powder indicate to me the right powder is happy with the right primer. Zero ES puts the exclamation point on this notion. Due to the placement of the 53.0 shot at the top of this ragged group, some positive compensation may exist. Powder was weighed to the kernel. Good stopping point.

Might have a few typos in your post there. No way you're pushing 53 gr of H4350 in a Creedmoor case.

Seymour Fish · Oct 15, 2024

Harman117 said:
Might have a few typos in your post there. No way you're pushing 53 gr of H4350 in a Creedmoor case.

You failed to notice “270”. Both calibers like H4350, so my comments apply in a broad sense

WasNH4X · Oct 15, 2024

Harman117 said:
#1) Following the basic "How to setup" FL instructions aka thread the die to the shell holder +1/8 to 1/4 turn often oversizes the brass (too much work being done) which can even lead to case head separation. Hornady makes a Headspace Comparator set for low $ that works with most calipers (assuming you have those). Watch the first video a few times and start setting your FL die appropriately to YOUR rifle using the method described.

#2) Yes, I could see how it's confusing, a lot of different people talking at once to you. You want both a FL die (remove the expander ball) and a Mandrel Expander die. Think of it in this high-level way: the FL die sizes the outside of the brass by "squeezing it" down to size, then the expander mandrel will expand the inside of the neck/case mouth out to almost the bullet diameter. Just watch the second video a few times and it will be clear. I'd recommend the 21st century expander die (with viewing window) and their mandrels. 0.263" (0.001" under bullet diameter) and 0.262" (0.002" under bullet diameter) these mandrels will be enough to start. View attachment 8514520

#3) You should also be chamfer/deburring every time whether you trimmed the case to length or not. You don't want to remove a lot of material doing this, the goal is to eliminate sharp edges/burrs. Some expensive trimmers will actually trim, chamfer and deburr in one step, but they're $$$. You can go the powered route, but a nice hand tool will also work and be much lower cost. A lot of people make chamfer/deburring tools, I'd recommend one that is a VLD profile. View attachment 8514521

You do those 3 steps and your ammo will improve drastically, without dropping a ton of coin.

Sound advice, the only thing different that I'd advise is to get a k & m chamfer tool, because the depth of chamfer can be set ,resulting in consistent chamfer for each case.

260284 · Oct 15, 2024

_Thor_ said:
My powder/primers/bullets are generally same lot for any batch I'm doing, though the brass is very likely not as it's mixed up brass I've processed in batches. I would hope the hornady digital scale I have is accurate enough that I don't need to upgrade immediately - I believe I'm using the Hornady G3-1500. I've bought some Lapua brass so hopefully I'll get some better results as this will obviously be from a single batch, but also better brass.

I'm shooting this in a Tikka, recently rebarreled with a 26" Proof Match Contour Steel barrel. Besides the lapua brass I'm about to try, I've also grabbed some 144 Berger LRHTs and Barnes match burners to try. I am sticking with LRP right now because I have a fair number of those, more than SRPs.

Don't worry too much about load development until you get 100-200 rounds down your barrel, it will speed up. Measure the OD of the neck of a loaded round to see how much neck tension/ what size of bushing you need.

_Thor_ · Oct 15, 2024

WasNH4X said:
Sound advice, the only thing different that I'd advise is to get a k & m chamfer tool, because the depth of chamfer can be set ,resulting in consistent chamfer for each case.

I already picked up the Burstfire one linked earlier in the thread, but I'll try to be as consistent as I can by hand!

260284 said:
Don't worry too much about load development until you get 100-200 rounds down your barrel, it will speed up. Measure the OD of the neck of a loaded round to see how much neck tension/ what size of bushing you need.

I have about 400s round through this barrel, so I think I'm in the clear there. I did measure the OD of one and found it at .291, so the .289 bushing I was using seems appropriate.

I have a few permutations planned now, but besides that I have some interesting things going on as I try to determine seating depth, which I asked about in another thread. Currently I'm debating whether for these other permutations I should also try the new/deeper seating depth or if I should stick to the one I've been using which at this point seems to be well into the lands.

Seymour Fish · Oct 15, 2024

Seymour Fish said:
You failed to notice “270”. Both like H4350, so my comments apply in a broad sense

“Cartridges “

260284 · Oct 15, 2024

_Thor_ said:
I already picked up the Burstfire one linked earlier in the thread, but I'll try to be as consistent as I can by hand!

I have about 400s round through this barrel, so I think I'm in the clear there. I did measure the OD of one and found it at .291, so the .289 bushing I was using seems appropriate.

I have a few permutations planned now, but besides that I have some interesting things going on as I try to determine seating depth, which I asked about in another thread. Currently I'm debating whether for these other permutations I should also try the new/deeper seating depth or if I should stick to the one I've been using which at this point seems to be well into the lands.

I have had great accuracy with the 140 ELDM out of a 260 and my 6.5 Creedmoor. I use Peterson SRP brass, Rl16, .002 neck tension, and .065 off the lands. Look up the Satterlee seating depth method. I use a bushing die and no mandrel, single digit SDs are pretty easy once you are consistent with your reloading.

Barelstroker · Oct 15, 2024

GBMaryland said:
I found that Norma made Prime brass had a SD of 4 in my initial work up… 6 SD when the sample size opened up to 50.

If I may ask.
What does it mean to have a "6 SD"?
What do you anticipate over the long term with a velocity SD of 6?

GBMaryland · Oct 15, 2024

Standard Deviation

Standard deviation - Wikipedia

en.wikipedia.org

You goal when reloading is to get your rounds to be traveling as close to the same muzzle velocity as possible. This causes the only other factor to be that of the shooter, generally.

For example, I went to the range and tested some 6mm Creedmoor... the Berger had an 11SD, the Normal had a 9SD, and the Hornady had a 34SD. (34 Standard Deviations from the mean average... which is pretty shitty, and indicates that 6CM Hornady has some serious issues.)

You want all of your reloaded rounds to be as close to each other as possible. Ideally, they'd be Xerox copies of each other... However, manufacturing processes being as they are, you get differences in one piece of brass to the next (internal volume), differences in the explosive force of one primer to the next, differences in the amount of powder from one charge to the next, etc.

What you can control is the exact amount of powder thrown, and what brand of brass you use. Plus, you can prep all of the cases the EXACT same way, resulting in far lower SDs.

straightshooter1 · Oct 15, 2024

Barelstroker said:
If I may ask.
What does it mean to have a "6 SD"?
What do you anticipate over the long term with a velocity SD of 6?

In trying to make is simple to understand. . . 6 SD means the the "average" spread of 6 units (+ and -) from the average for the total. For a 6 SD, that's a spread of 12 (+6 from the average AND -6 from the average). The less you are from the average of the total means your more consistent (e.g. small SD's) and of course, the farther you are from the average (average referring the the mean of the set) the more inconsistent.

Keep in mind that the larger the data set the more reliable the SD numbers are. e.g. an SD of 6 for 3 data points isn't going to really tell you much (like how reliable) as a data set of 50. The larger the set of data, the more reliable the SD number is have real meaning for you.

Velocity SD's are a good measure for how well you're prepping and loading your cartridges. IMHO, 10-20 velocity data points tends you give me enough confidence in what I can expect from the next shot or not.

45-90 · Oct 15, 2024

Seymour Fish said:
Using h4350 is the easy button. 270’ 140 Berger vld, ancient mixed fed brass, fed 210m, seating .012” off at random, ladder from 50 gr to 53 gr in .5 gr increments went in a ragged hole .75” at 100. The 53.0 felt and sounded best. This is perhaps a key often overlooked. The 53.0 shit .205” with anES of Zero. 2970 across 5 shots. No rest or bipod, just some crap bags. The hold included hard pull to shoulder and firm grip on forend, a hunting hold for an 8 lb rifle. Quality 30 yr old 24” bbl. Nodes across 3 grains of powder indicate to me the right powder is happy with the right primer. Zero ES puts the exclamation point on this notion. Due to the placement of the 53.0 shot at the top of this ragged group, some positive compensation may exist. Powder was weighed to the kernel. Good stopping point.

So you ran 2970 fps with 140 gr Bergers a old 270 Win with a 24" barrel.
You used H4350 so your comment applies in a broad sense...How?
It's about 6.5 CM.
H 4350 dies well many cartridges, especially the 6.5 CM.

Sounds to me like your just trying to hype the 270 Win over the 6.5 CM as better....it may be in certain applications.

But back to the 6.5 CM.
One can greatly improve performance of the 6.5 CM cartridge.
Even though the orginial post was trying to get S/D low for best LR accuracy.

With a factory 24" barreled 6.5 CM and hybrid cases I ran 140 gr bullets to 3156 fps.
But the 150 gr SMK were excellent at just over 3000 fps.
Do not even think about trying this without hybrid cases period.
At least it applies to 6.5 CM, it's fast and accurate in my rifle, and out performs most "270s".
This is not needed or desired by many LR shooters, but it's about maximum performance available in 6.5 CM at this time.
Back to the 6.5 CM loads for normal shooters, H4350 it's not the fastest, it doesn't have to be, but it's one of the most consistent, and why I'd stick with it for a basis of comparison in testing, to build off of, regardless of match bullet used.

Barelstroker · Oct 15, 2024

GBMaryland said:
Standard Deviation

Standard deviation - Wikipedia

en.wikipedia.org

You goal when reloading is to get your rounds to be traveling as close to the same muzzle velocity as possible. This causes the only other factor to be that of the shooter, generally.

For example, I went to the range and tested some 6mm Creedmoor... the Berger had an 11SD, the Normal had a 9SD, and the Hornady had a 34SD. (34 Standard Deviations from the mean average... which is pretty shitty, and indicates that 6CM Hornady has some serious issues.)

You want all of your reloaded rounds to be as close to each other as possible. Ideally, they'd be Xerox copies of each other... However, manufacturing processes being as they are, you get differences in one piece of brass to the next (internal volume), differences in the explosive force of one primer to the next, differences in the amount of powder from one charge to the next, etc.

What you can control is the exact amount of powder thrown, and what brand of brass you use. Plus, you can prep all of the cases the EXACT same way, resulting in far lower SDs.

I thought as much.
So, with a well established SD of 6, what should we anticipate as a realistic ES over the long term?

Barelstroker · Oct 15, 2024

straightshooter1 said:
In trying to make is simple to understand. . . 6 SD means the the "average" spread of 6 units (+ and -) from the average for the total. For a 6 SD, that's a spread of 12 (+6 from the average AND -6 from the average). The less you are from the average of the total means your more consistent (e.g. small SD's) and of course, the farther you are from the average (average referring the the mean of the set) the more inconsistent.

Keep in mind that the larger the data set the more reliable the SD numbers are. e.g. an SD of 6 for 3 data points isn't going to really tell you much (like how reliable) as a data set of 50. The larger the set of data, the more reliable the SD number is have real meaning for you.

Velocity SD's are a good measure for how well you're prepping and loading your cartridges. IMHO, 10-20 velocity data points tends you give me enough confidence in what I can expect from the next shot or not.

I thought as much.
So, with a well established SD of 6, what should we anticipate as a realistic ES over the long term?

GBMaryland · Oct 15, 2024

What’s really gonna change is how well you’re able to shoot as the circular error probable (CEP) will be huge when you have significant changes in feet per second of the bullet as it travels down range.

Circular error probable - Wikipedia

en.wikipedia.org

For example, I just did some testing of some hornady 6 mm Creedmoor… And the outlier was well over 100 ft./s different from the average velocity.

I’ve had a barrel speed up on me before after a few hundred rounds. That difference was only 75 ft./s, and at 700 yard my dope was so off that I was shooting over the target.

If my bullets were 75 ft./s off from one round to the next in either direction I would be missing the target and shooting the berm below the target or the bottom of an 800 yard target, because things were so wacky.

Typically, the two major things that affect that are charge weight being consistent, and the internal volume of your brass. This is why people go out and buy auto trickelers, and go out and buy Alpha, Peterson, Lapua, Norma, or other high-end brass.

(To be fair, you can go out and buy brass, such as Winchester, Remington, PMC, Federal, Hornady, S&B, Speer, Starline, etc., and sort the hell out of that brass by weight… thus lowering the overall SD.)

Also, part of the reason people clean the living hell out of their brass is so that they get all of the excess stuff off the brass so that when they sort it, they actually get accurate weight numbers…

If you have an SD somewhere in the 10 range, then you can shoot all day long and be pretty damn consistent hitting targets with the same point of impact through your scope. (Provided you’ve worked out your dope all the way out to your intended target)

I’ll add some pictures to this to make it more obvious.

RegionRat · Oct 15, 2024

Barelstroker said:
I thought as much.
So, with a well established SD of 6, what should we anticipate as a realistic ES over the long term?

Approximately speaking, if the distribution is fairly normal and the SD=6 from a good sample, and you kept shooting, you would come close to an ES of roughly 36.

ETA: the basic principal of the ES of a "normal distribution" is that the two "tails" of the distribution span roughly six sigma, so 6x6=36

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