Disclaimer:  I've loaded a good number of .223 rounds over the last 15+ years, but almost always looking more for quantity over quality.  I'm trying to better develop some "quality" loading skills.

With larger cartridges, I don't even have to "try" to get SDs in the low double digits; 10-15 range.  Just use same headstamp brass, consistent powder charges, and decent bullets, and I'm there.

With .223 it doesn't seem to be the case.

LC same year headstamp
Consistent charge, specific powder seems largely irrelevant so far
77gr SMK
Rem 7.5

Most 20rd samples give SDs in the mid 20s to mid 30s.
This seems pretty high.

The only thing that stands out to me is that the LC brass shows extreme spreads in weight of nearly 2gr, which represents pretty high percentage variance compared to the lots of decent 308/6.5 creed that I have.
However, it still seems to be the most consistent weights of any 223 brass I've closely examined so far.

I have some factory Black Hills and IMI Razor Core; I guess I should shoot some more of that and pay attention to the SD to get a baseline.
I'm wondering what others get.

None of those are particularly bad, none.

10-15 fps could be really good, as long as it's based on a large sample.  Any SD number whether high or low is meaningless if it was obtained from a small sample.

Whether the values are acceptable depends entirely on what you plan to do with the ammo (the use case scenario).  That is, unless chasing low SD is an academic study (which is not a bad thing).

If you want the best possible uniformity in brass weight, just go buy some LAPUA.  You can then test to see if the brass weight variation is the cause of your higher SD.


What powder are you using?

How do you do your powder charges, hand-weighed or dropped?

Ultimately the use case for the 223 is local DMR type competitions I've taken up recently, with targets out to ~600 from various field type positions.  I really doubt the ammo is the primary factor/lowest hanging fruit in my total game there, but at the same time, if I could improve it, why leave it on the table.
~30fps just sounded high to me when everyone seems to be chasing single digit SDs.

The main two powders I've used are AA2520 thrown from a measure (weighs bang on every time I look) and Varget (hand trickled).

I've done some cursory looking for some .223 Lapua brass, seems to be out of stock, but I guess I should look harder or just pay out for their factory ammo...

You might try switching primers; I get the best results with WSRs and my powders of choice - RL-15, RL-15.5 and N-550.  I typically shoot 75 gr bullets at 2930 fps and consistently get SDs of 10-12 for 10-shot strings.  I recommend getting trays of as many different primers as you can get your hands on to test with your bullet/brass/powder.  

Accurate charge weights are a necessity as 0.1 gr of powder is worth 16 fps; I weigh my charges to +/10.02 gr using an A&D fx-120i scale (0.02 gr resolution) thrown with an Autothrow/Autotrickler (the automation really speeds up the process vs. manual trickling).

A difference of 2 gr in case weight would change velocity by 12 fps in my testing, so selecting narrow range(s) of weight would help; I choose to sort into 0.5 gr lots for my long-range brass (800-1000 yd).  

Neck turning to get consistent bullet pull is less of a factor, but makes a measurable difference.  I anneal my brass after every firing so that bullet pull doesn't change as the brass work hardens with each firing/resizing cycle; at least segregate your brass so each lot has been fired the same number of times.

In my experience with Lake City, don't even bother to sort by year, it isn't like there is one lot a year. I'm not convinced case weight is a direct indicator of case volume either. It must be better than nothing, but I'm not sure weight sorting is going to cut your velocity spreads in half. You can certainly try it though. For me one of the most important factors has been neck tension. Annealing cases really does help consistency. One of the problems with using random brass like this is the neck thicknesses vary, they are fairly thick necks too. I've seen annealing bring velocity ES's from 60 down to 30 before. Usually Varget is one of the highest rated powders, so I don't think that's really an issue. I've always had good luck with it. I can't help with specifics on 223 as I never tried that hard with it. My current load is a 60gr V max and AA 2200. I honestly have no idea what the speed even is, I've never tested it. Sorry I can't be more help.

+/- 30 fps is only 1" in windage at 600 yards and only 3" in drop (assumed 2600 fps).

Those are 1/2 MOA or less, especially when folded into an overall error in point of impact.  

Is that where you need to focus your efforts, or would dry fire practice at home be more beneficial?  That is is the type of thing you should be considering.  For a newbie to a competition, I'd bet a buck dry firing from position is more important.


What group sizes are you shooting right now?

On the higher end, but normal. 15 is about as good as it gets with respectful handling. Lower than that needs money, work, and/or time in annealing, neck turning, etc. I am a proponent of flash hole deburring with it being a one time job. I haven't gotten around to pocket uniforming yet.

I've taken to Borderpatrol's method of lubing a case while another is in the sizing die. Raise the ram smoothly, almost gently, but consistently. A touch of Hornady Unique (Imperial) scraped into two sides of the mouth and the remainder wiped on the body. Lower the ram smoothly, consistently.

Sort ammo by seating resistance. If one is obviously easier or harder to seat, save it for foulers.

What barrel?

So many factors go into low SD/ES numbers….

In my experience, it’s mostly controlled by charge weight variance, type of powder and the charge value itself.

Obviously controlling your charge consistency down to the kernel is ideal, but not always practical. I use an AutoTrickler with the FX120 scale… it’s amazing. I don’t have to worry about variability when I’m doing work ups, because it’s basically as good as it’s ever going to get. Weighing your charges and trickling them as best you can will yield better results. Having a quality scale with no drift is a must!

Next is the type of powder. Ball powders generally won’t give as good of SD numbers as stick powders. Staball Match is the best ball powder I’ve tried with regards to SD’s. Not all stick powders give great SD’s either, some are better than others. H4350 and AR Comp are the two best I’ve tried (I’ve tried a lot).

SD’s change with the charge weight, the exact same way accuracy does. Typically, the low SD charge weight and the best accuracy charge weight are NOT the same, unfortunately.

-ZA

Was finding that when developing loads for my RMR 68 and 75s. Got way better accuracy from 30-40 SD loads but as I went up in powder charge and reduced the SDs the groups opened up.

SD does not always directly correlate to tighter groups, you are going to spend a lot of time and money chasing a smaller number when its very likely not going to matter much to the end result on target

work up a load that groups good and is within safe pressures

What chronograph?

The “experts” say the most likely culprits in ruining SDs are neck tension, sufficient chamfer/de-burr, primers and then powder.

Maybe your die has an imperfection, or the expander? You can always try case sizing without the expander, then run your brass over an expanding mandrel like a 21st century .2220.

If you want to try a faster burner, maybe work up Power Pro 2000MR or Varmint. Could try Benchmark if you prefer Hodgdon.

It is a fallacy to think a few fps or a few tenths of MOA will have any measurable effect on your targets.  You're leaving nothing "on the table", as any changes you make are immeasurable unless you are already shooting 1 MOA or better.

If you are unfamiliar with error analysis, this may (probably does) sound like BS to you.  Errors do not simply add together (or subtract from each other).

Improve your shooting skills, instead.

I have to agree.

I have fallen down a rabbit hole or 100 in rhe last 44 years of shooting / reloading 25.

Idk if anyone is good enough to see the difference at 600 of 30fps sd with a 223.

I’ve never caught a day that was calm enough I believe anyone could measure that.

Maybe the guys who shot at the warehouse in Houston.

I think you would have to shoot inside to have any hope of seeing it.

As much as it goes against my intuition, an SD of 20+ fps on a group of 10 shots really means nothing. I use a V4 trickler, so I know my charges for 600 yard high power matches are exact. I've shot plenty of good scores with ammo that has SDs like yours.

Every once in a while I'll get a single digit SD when testing, but it's not that often. Most of my SDs are in the teens.

I think brass prep helps me. I set my caliper at 1.76". If the brass fits, I'll reload it. if it's too long I trim to 1.75" and chamfer. Clean the primer pockets. Also like others have said a 30fps spread doesn't affect accuracy on steel targets too bad.

Neck tension.

You are using same lot LC, but are they all the same number of firings? If you’re using once-fired beside 7x-fired you’re going to get a broad SD unless you anneal and establish a uniform hardness baseline for all your brass.

Anneal mixed brass to establish a baseline, debur, clean inside necks (I.e., no lube randomly inside some), use a bushing instead of a mandrel, and you’ll see the SDs you are looking for. Neck turn if you really want to get all the way there.

There’s a kid on the USAMU whose mom (yes, his mom) is so rigorous with brass prep that her 5.56 SDs are single digit.


ETA: for those saying low SD isn’t needed for accuracy, remember OP is competing out to 600 yards. You can’t be accurate with 5.56 at 600 yards with crappy SDs.

Thanks everyone for the thoughts... a lot to potentially address here so I'll hit what I can remember scanning through...

1) Would practice shooting represent a better improvement than ammo improvement, absolutely, tremendously so.  I don't consider it an either/or proposition though.  Working up to GM in the pistol world, everything matters, everything that can be controlled must be improved, so that is my default mindset here.  Unfortunately I don't currently have a place to live fire practice/test past 300yd, so addressing that is by far the biggest item, and will be addressed, but again, I don't consider these items mutually exclusive, or either/or.

2) Brass is sorted by number of firings, I recently got an annealer to mess around with, but very early returns don't seem to suggest an improvement, I will definitely keep working with it though.

3) Primers, good point, I can do more testing along this line.

4) Chrono is a Garmin

5) Barrel/accuracy, I've shot these loads in many barrels and there doesn't seem to be a big difference in SD barrel to barrel so far, but I'll keep paying better attention now as well.  The one I'm currently shooting in the competitions is a G Super Duty 16".  With the Mini2 on, it is my most accurate AR setup for sure.  For me, bench/rested at 100 yd shooting with an LPVO, it is really, really close to an honest 1.5 MOA "all day" rifle.  Meaning about 9/10 in any given group are usually sub 1" and if there is a "flyer" one will open it up to 1.25 to 1.5".  At 300 in the same conditions and setup, groups are usually an honest 5-6".  This is counting all the shots and not cherry picking anything.  Again, this is off a bench eliminating as much shooter error as I possibly can, and certainly not reflective of what I'm shooting from field positions on the clock.

Im going to parrot a few points here, but mostly to drive them home...

Brass and powder charge are the 2 things that affect ES/SD values the most.

Powder charge will only change ES/SD alot of its a wildly different charge.  The one thing to bear in mind with this as that 223 has alot less case capacity than 308, thus makes it more difficult to get better numbers over the chrono, which is what you have seen.  Normally you would see a point where you will get a .2-.4gr spread where the powder charge being off a bit isnt really going to affect ES/SD that much.  You can explore this and see it in action when shooting Satterlee tests.  All I can say for powder is just keep your charges within +/- .1gr and thats honestly about good enough unless youre running something like an AutoTrickler that does all the heavy lifting for you here.

Brass is usually the biggest culprit in bad ES/SD.  Case capacity is the one cause here, especially if youre using LC brass.  I dont believe year sorting is worth the time as it can vary even during the same year quite a bit.  Weight sorting can get you closer but will really only remove the major outliers.  I generally expect SDs in the high teens with LC brass, expect worse, hope for better.  Next would be neck tension.  Neck thickness on LC brass will vary, and due to that neck tension will vary as the brass ages and work hardens.  You have 2 ways to fix this.  Start annealing.  Bringing all the neck tensions to a uniform value will help.  Neck turning.  Once again, this will help produce uniform neck thickness and neck tension.  Last thing I would consider doing is using a mandrel to set neck tension instead of the expander ball as it seems to give better results for concentricity purposes.  

You can go down the uniform primer pockets, flash holes route as well.  Fortunately you only have to do it once.  But my feeling is that its one of those things that is really hard to verify youre actually doing anything.  Like the old saying goes "I do 20 things to prep my brass, but probably only 5 of them make a difference.  I just dont know which 5 it is so I do all 20"

If ultimate accuracy is what you need?  Youre going to probably have to start with better brass.  Starline is decent and Ive had decent luck with it in 223, 308, 30-06 and 6 Grendel with holding SDs in the range of 8-17ish, but it pales in comparison to the SDs of 3-8 I see with my Lapua and Peterson brass in 308, 6 CM, 300 PRC.

I agree with everything Kaldor wrote, but I’ll also say you can get there with LC brass.

In 2019 (my last competition year) I shot clean 600 yard targets for my last 3 matches in a row. You could call that an interrupted 60 shot sub-2moa group. It was all LC brass.

I just pulled up the screenshot of the ShotMarker target from the last of the 3 and my SD at the target was actually 20. I didn’t remember it being that high. But there it is. You can shoot sub-2moa 600 yard groups all day long with a SD of 20. Hopefully that helps reduce your concerns about your SDs.

Reducing SDs below what you already have will only affect shooting at long range (800+ yards); it matters to me because I shoot Palma competitions, so sub-MOA bench accuracy is necessary.  The X ring on the NRA 1000 yard target is one MOA and the ten is 2 MOA.  If you're going to win anything at the national level, even as an Expert or Master, you need to shoot clean with a high X count under mild conditions.  There needs to be some margin to allow for operator error.  Wind drift at 1000 for a Palma load is approximately 1 MOA per MPH, so even the best basic accuracy requires very good wind reading skills to avoid dropping points.  Palma rules require the use of .223 or .308; in other disciplines you can usually choose to use a cartridge with better ballistic performance (my non-Palma LR rifle is a .284, a common choice in F-Open).

It can be done with LC brass, but it takes more work.  Some of the best groups Ive shot from my target built gun have been with LC.  
I anneal, FL size, trim and mandrel all my LC, but it goes into a bucket to be loaded from there.  I draw the line at neck turning for an AR though.  Just not worth the time IMHO.

I don't have much new to add - many excellent replies and just read this as a me-too.  

That' SD isn't that bad, especially for .223.

.223 (And the AR15) are REMARKABLY forgiving.  you can have SD's in the 50's or higher, and still shoot 1 MOA groups.  It's just a really forgiving round.  

In my experience in competition, An SD like that can be match-winning ammo at 600 yards all day long, it's just not a limiter.  It'll hit the same spot on the X-ring just fine.  

I will say, once you start reaching out to 1000 yards, I learned the hard-way all kinds of things start showing up, that you don't see even at 600 yards.  But even at 1000 yards, a 10-15 FPS SD isn't that bad.  But you'll start to see it on target.  I've had 30 FPS differences drop me entire score rings, at 1000 yards; which you'll never see at 600.  But rarely is a .223 round a 1000 yard round.  If your goal is great groups out to 600 yards, 10-15 fps SD isn't really going to be your limiter.

but to your "frustration", I too find that for whatever reason, it's just hard to get the SD of the .223 down as low as some other rounds.  It doesn't show up on paper, but it does show up in the chrony, and I just don't really know why.  

As an aside, did anyone else see GarandThumbs video on the new Army rifle in the Sig-Fury round?  I don't youtube watch a lot of content, but I did watch that one.  He set up a GARMINE and his MV with 133 gr ammo in that short barrel was over 3000 FPS; which is indeed quite impressive - I have to admit.  But what was mindblowing was the SD was 3.

About 10 years ago I conducted a test with a .308 bolt gun. It looked at the relationship between case length (realy neck length) and velocity. Two velocities are from the Proof Channel in my P35 Oehler. Like I said, it was a long time ago.

As you can see there is a relationship. If you are not trimming each time, you are contributing to increased SDs. How much does it really matter? That's debatable based upon your application.

That’s an interesting test, thanks for sharing!

Neck turn to get rid of the donuts.  Mixed headstamp LC brass needs Benchrest preped, sorted by weight.  Like the test i did.

I don’t know, I have been rethinking a lot of my efforts at the bench lately.  With 223 in particular.  

I find with some (ball) powders I just need to push them hard enough to get consistency.  For example below is 25.5gr of TAC with 69gr RMRs.  But things dropped on a Dillon with MIXED brass.  I do trim (Giraud) after resizing and apply a very light crimp, but I don't weigh brass/bullets, anneal, or any of that.  I tested a 25rd set last month with an SD of 9, so it’s pretty consistent.  But it’s a bit spicy with the weather heating up and I lowered to 25.2 with the batch of 500 i just loaded.



With other cartridges I absolutely see the merit, but it seems like the less picky I am about my brass the lower my SDs seem to get.  Even my 77gr SMK 8208 loads, which are mixed year LC, I stopped weighing every charge and went to loading on the Dillon and am getting single digit SDs that are almost exactly in line with the results I got weighing each charge.


Now out of my 12” I do get SDs of 15-20 with the same 69gr load above, both are wylde chambers… maybe I’m just not getting as complete of a burn.

Another thought - how firmly and consistently do you shoulder the rifle?

I checked these chrono readings a few different ways and could not confirm they are correct in any way.  Put another way, I find them to be anomalously high.

25.5 gr of TAC from a 16" barrel in a 223 case does not produce 2930 fps for a 69 gr projectile.  

Then again, that is off-topic, so I will end this here.

Don’t know what to say, it matches my workup experience from 2022 with the same 16” WOA, but that was loaded on a powder dispenser and measured with a labradar.  But i didn’t note weather when I posted that in a thread in June of ‘22 (LINK) and actually reached that velocity at 25.3.  So different scale and different measuring device with consistent results so i tend to trust them with this bullet and powder combination since I have multiple data points to rely on.

But I guess if you “confirmed” them in some different way, believe what you want.  But I have seen and posted in here before about some pretty significant variances in lots of TAC but I think these came from the same order of a couple 8lb jugs but I’m not positive if from same lot.



But to get back to OP, I again saw lower SDs here with TAC as I pushed it a bit harder where some powders like 8208 didn’t seem to track the same and seemed to get worse at the limit.

And note that the above target was with mixed year LC brass that I was using for load development.  I again saw lower SDs with the ones I posted earlier with mixed brass.  Now I am in no way going to saw that mixed brass should give a better SD, only pointing out that the difference between 223 brass isn’t as significant and doesn’t seem to have the variance of other calibers.

Kaldor nailed it. Good job.

Small case make minor details important if you are going to chase SD. Whatever changes you are making, make sure it will matter first before you invest too heavily.

Test at the range you will shoot, that will tell you if there are problems in the system. Close ranges can be deceptive unless all you are going to shoot is close range.

Historically, I have gotten best accuracy with stick powders vs. ball.

Are you measuring for length ?  A longer case will weigh more than a short case.  I have found a big difference in Lake City brass.  As short as 1.740 to as long as 1.770.  If you use the roll crimper built into your seater die you will have crimps all over the place if your lengths are different.  The same with neck tension if the cases are as much as 30 thousands of an inch different.  I don't weigh, I put in groups within 5thousands of each other.  Small group is 1.745 to 1.750.  Next group is 1.751 to 1.755.  Next group is 1.756 to 1.760.  The last group is 1.761 to 1.765.  

OR you can trim them all to one length.  The usual seems to be 1.750.  I like to group for different guns and different bullets.  The shorter the bullet (50 grain or 52 grain) I like to use a longer case.  Especially if it's going into my Remington 700.  That is my most accurate gun and it has a 1/12 twist.  I like the longer necked cases for those lighter shorter bullets so I can get them closer to the lands.

If you are using bulky stick powder you want a longer case as well.  You can't get 24.6 of 3031 in a 1.740 case.  You need a minimum of 1.750 and hope the powder sticks landed the right way coming out of your powder measure.  Or don't worry about it and use either ball powder or use a longer case.

I also resize my cases to fit in different chambers.  My bolt action .223's are the tightest chamber and the AR's are the loosest chambers.  If I resize a case for the AR's the bolts actions will not close on them.  The shoulders are too far forward for the tight chambers.    I use a Hornady Comparator to know just how far from the base the shoulders of the case are.  For the .223 I use the A330 Hornady bushing.

It's a lot of measuring but it seems to pay off with accurate ammo.  Spend 7 minutes to watch this video.

Tracked this article down, a little OT but I assume it’s what y’all were referring to:

https://precisionrifleblog.com/wp-content/uploads/2013/10/secrets-of-the-houston-warehouse-by-dave-scott-precision-shooting-magazine-special-edition-1-1993.pdf





I think we’ve been at some of the same matches then.  I didn’t shoot any last year due to an injury but am shooting a second one this year in June at Clinton House.

I got my 77gr SMK loads into the teens SD wise with Varget and either BR4 or REM 7.5 primers.  When that runs out, I’ll be reverting back to RE15.  Like you said, I doubt a single digit SD is going to make the difference in how I shoot in a 600yd match but I’d like to make sure the ammo I’m using isn’t a factor in any errors I might make

Thanks all, lots of good stuff to think about, I appreciate everyone's input.



Yes, those are the ones I'm talking about.  The June one is on my radar.  I was originally planning to skip it since I haven't had a chance to shoot that far in a practice setting, it seems like a "waste", but, since they are really only happening about every quarter, just the additional experience would probably be good.

I also just came into a batch of once fired Norma brass that is measuring noticeably more consistent weights than the LC, so while I don't have that much of it, I can do some loads with it to see if the numbers look better.

"Thank you to Editor Dave Brennan, his employees, and his ranks of writers for the years of thought-provoking reading."

Ditto!

If you are feeling frisky for some old PS magazines, someone has been digitizing them and uploading them to the Internet Archive.

Looking through the old editions there are some really interesting articles that I only heard old timers talk about when I was younger. Nice to be able to read the actual articles. There is also a lot of crap but overall worth the price (free).

I was shooting my match load (24.5 grains of Varget, Winchester brass, BR-4 primers and 69 grain SMK's seated @ 2.250") through my 26" Winchester M70 heavy barrel varmint rifle and the SD was 15. It's worse than that through my 20" service rifle, and a lot worse through my 16" carbines. Same ammo, different barrel lengths.

A carbine wastes a lot of pressure when the powder charge evaporates into thin air after only 16" of barrel. It's hard to get an efficient burn from any powder with that barrel length.

IME, ball powders produce tighter SD's, at the expense of higher pressures when the temperature rises. I simply won't use them. In my reloading journey I have settled on extruded powders as my go to. They seem to have a wider accuracy window, even when thrown, they still shoot very well out to 300 yards, and they never give me headaches when July and August roll around.

I gave away 3 big boxes of back issues of PS to make some room in the garage.  I mailed to to someone who wanted them at no charge.

I kept all of the issues of their short-lived Tactical Shooter magazine.

Although its orientation was "tactical", it really had a lot of practical shooting tips.

I agree, at short ranges like that, SD just doesn't matter (within reasonable limits).  

Some of your old mags may have been preserved in perpetuity! Thanks for donating them.

1) Would practice shooting represent a better improvement than ammo improvement, absolutely, tremendously so.  I don't consider it an either/or proposition though.  Working up to GM in the pistol world, everything matters, everything that can be controlled must be improved, so that is my default mindset here.  Unfortunately I don't currently have a place to live fire practice/test past 300yd, so addressing that is by far the biggest item, and will be addressed, but again, I don't consider these items mutually exclusive, or either/or.

OP:
Very well put…………excellent thought.

To your question:
Usually with 223 I’m like the others where 10-20 SD is the norm.
I shoot 223 in Service Rifle (out to 600) and 1000- in Colorado elevation- it’s easily done, though not ideal.
So like you, I do look at simple or reasonable things I can do to improve my shooting.

I stumbled across a load during testing that had EXTREMELY low and consistent SD……..as in single digits!
As in right around 9 consistently……….

It was with LC -pulled- primed brass that I had neck sized and 2520 powder.
I grouped the brass by head stamp- so same year- and ran it thru my neck sizer with the decapper removed.

So what I got out of that and other testing I’ve done is:
-LC brass is perfectly good for what I do.
-Try different primers and see what you get.  Some powder/primer combinations seem to just “play well together.”
-Try and play with different tension “settings” on the bullet, see if that makes a difference.