How many rounds for load development?

[PiratePast40]

How many rounds are people loading to test different powder weights to determine a good, overall load? The ammo will be used in standard AR platform rifles for general range use, plinking, and running drills. My plan is to load 9 rounds at each powder weight. 3 will be for shooting across the chrono and will be used to determine pressures by inspecting primers and cases, velocity, and ability to cycle. Will be getting a rough idea of accuracy by putting a target out at 15 yards. Will shoot another 3 at 50 yards and 3 more at 100 for accuracy.

55g FMJBT, H335 powder, 2.225" OAL, range brass. Will be testing 24.7, 25 and 25.3grain loads.

I've got different powders to try and more sophisticated projectiles, but for this first go round, I'm just looking for general purpose ammunition. Any comments or recommendations?

I've done plenty of testing and reloading with 9mm so am familiar with the process, just beginning with 223 and thought I'd ask around.

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[wombatz]

Only suggestion would be to chrono while shooting at a target to get better economy.

Edit:
Oh, I guess you are already doing that. I had trouble counting all the way to 9.

 

[orygun]

I did a ladder test a year or so ago for the first time. I loaded 5 rounds each of different charge weights. I also mirrored that with 5 rounds each with a different primer. I ran them all over the chrono and watched group size closely.

I didn't get all the way to the top loads when I found a spot where the gun was crazy accurate. I stopped there.

 

[arrowshooter]

Unless I am starting with a new optic, I only do 3 each to find the accuracy. FPS is secondary. I'll then pick the most accurate then go 5 each of that plus the step below and above to confirm.

Spoiler alert: 25 gr of H335 is recognized as the "standard".

 

[415DET]

+1 on the 25g of H335. It has been the best load for all of my 52-55 grain bullets in all of my 223 Wylde chambers.

 

[oremike]

First off it takes what it takes to get where you want to get. Only you can decide when you are there. That being said, my OCD likes 5 shot batches because that is one row in the loading block. I make a row all the same then skip a row, then make the next row with whatever adjustments I'm testing. One load block, 5 different loads. I don't like to shoot for group thru the Chronograph. One thing at a time for me. One I've got my pet load, then I'll shoot over the chronograph just to see how it compares to the rest of the world, but I'm much more interested in accuracy than speed. There is no industry standard for messureing the speed so the best I can do is on this day with my gun and this load I got this speed.

 

[PiratePast40]

From what I've read on multiple forums, many are saying that 25 works best for them. That's why I was staying close to that number. I was originally going to do 24.5, 25 and 25.5 but thought I'd stick closer to 25 and see what worked best for me without any getting close to any dangerous pressures.

 

[Catfishmoon]

I generally load five variants, 10 rounds each at .2 grain intervals...
I then shoot five rounds of each for accuracy and look for pressure signs on the cases; I don't have a chrono and I never load at maximum listed load data...
I then repeat the process on my next range visit to verify the previous results.

 

[PiratePast40]

I generally load five variants, 10 rounds each at .2 grain intervals...
I then shoot five rounds of each for accuracy and look for pressure signs on the cases; I don't have a chrono and I never load at maximum listed load data...
I then repeat the process on my next range visit to verify the previous results.

Between your comments and what @oremike wrote, I'm now wondering if using a chrono serves any purpose for this ammunition. My experience has been with 9mm and my concerns were power factor, and suitability for shooting suppressed. If those factors aren't there, and I'm inspecting for pressure signs, and not getting anywhere near max, I probably don't need to chrono any of these.

 

[Koda]

Between your comments and what @oremike wrote, I'm now wondering if using a chrono serves any purpose for this ammunition. My experience has been with 9mm and my concerns were power factor, and suitability for shooting suppressed. If those factors aren't there, and I'm inspecting for pressure signs, and not getting anywhere near max, I probably don't need to chrono any of these.

Velocity plateus are a sign of pressure. Velocities that exceed max published values with no other pressure signs are as well and indicator of pressure. I would not skip the chrono during any stage in load development IMO.

 

[Koda]

How many rounds are people loading to test different powder weights to determine a good, overall load?

Ive heard it done in as little as 15rds, but that was from experienced reloaders with a very specific bullet brand that does not align with most load data.

Im still new at this but from the beginning have tried to find the most efficient method, still havnt got there. Theres the OCW method, 3rds at each charge weight and shoot for best groups. Theres the Saterlle ladder where you shoot 1rd at each charge weight and look for horizontal POI alignment, then fine tune from there. Way more complicated but fans say most efficient.

Currently Im doing a pressure ladder, 1rd at each charge weight (min to max) until I find pressure, then back off a full grain and fine tune accuracy. But thats specific to that brand of bullet...

 

[orygun]

Between your comments and what @oremike wrote, I'm now wondering if using a chrono serves any purpose for this ammunition. My experience has been with 9mm and my concerns were power factor, and suitability for shooting suppressed. If those factors aren't there, and I'm inspecting for pressure signs, and not getting anywhere near max, I probably don't need to chrono any of these.

Not just for comparing to manuals for exceeding listed velocities, and possible pressures, I like the chrono to check for consistency. (low ES and SD)
Usually, but not always, consistency across the chrono matches with better accuracy.
Any given weight charge may show high ES and SD numbers. I'm always skeptical of loadings that are not speed consistent.

edit: changed dyno to chrono. Too much time in the garage!

 

[HotLoad]

I like to load 10rds per test case. I shoot all 10 through the chrono with 2 groups of 5 on different targets. That way I get good chrono data and 2 groups to determine accuracy.

 

[wombatz]

100% agree that if you have the chrono then use it.

If you follow load data carefully and avoid the top end then you can skip the chrono purchase. So not trying to say that it is required, but if you already own one then don't be lazy. Check any new loads that you develop.

 

[The Heretic]

I do 5 rounds of each increment (usually one tenth of a grain), while watching velocity and group size - also keeping an eye out for signs of pressure (flattened/cratered primers, sticking cases, etc). For me, group size comes first, then velocity.

 

[Hooyah DeepSea]

The ammo will be used in standard AR platform rifles for general range use, plinking, and running drills.

Just me speaking, but for these uses, cheap, factory ball ammo seems to be the more efficient source. On the other hand, if you are going for a specifically accurate load for, say 'yotes', then that would be worth the extra efforts.

 

[Ben B.]

Velocity plateus are a sign of pressure. Velocities that exceed max published values with no other pressure signs are as well and indicator of pressure. I would not skip the chrono during any stage in load development IMO.

Maybe. Or more likely they are an artifact of small sample size, which is a procedural error that is insidious thru most of the load development advice one hears.

The 2 professional ballisticians I've talked to urged me to place no weight on the "pressure signs" commonly discussed, as they can see these in tested low-pressure loads and can see no "pressure signs" in tested over pressure loads. Oddly enough, they recommended sticking to the book loads they labored to develop.

20 rd minimum for accuracy testing. You want to measure the dispersion accurately. If you do 5 shot groups, overlay them so you can measure the actual group size, and not just the 5 shots that happened to pile in top of each other on the one group and not the group that had the flyers.

 

[orygun]

100% agree that if you have the chrono then use it.

If you follow load data carefully and avoid the top end then you can skip the chrono purchase. So not trying to say that it is required, but if you already own one then don't be lazy. Check any new loads that you develop.

Funny thing about ballistics and what I learned when I got a chrono; Most pistols shoot slower than what's listed in the book and many bottleneck rifle rounds will exhibit severe pressure signs (cratered, not just flattened primers, sticky case extraction, etc.) before reaching max loads listed in the manual. What I noticed with the bottleneck rounds is that by the time I'm seeing the over pressure signs, I've already reached or exceeded the max velocities.

Just me speaking, but for these uses, cheap, factory ball ammo seems to be the more efficient source. On the other hand, if you are going for a specifically accurate load for, say 'yotes', then that would be worth the extra efforts.

As far as 223/5.56, I whole heartedly agree! I'm not trying to shoot tiny groups from my AR like I do with my hunting rifles. If I was, it would be worth the time and effort to handload. But time isn't easy to come by and I'd rather spend it doing things that matter to me.

However, @PiratePast40 asked the question because it must matter to him.

 

[Koda]

Some people are set up to mass produce range or training ammo, if they happen to develop a handload recipe thats super accurate all the better. When I was developing a hunting load for my AR I threw in a OCW test with some super cheap FMJ, groups were terrible then suddenly at one charge weight they went sub moa.
I only want a hunting load, but Ive been meaning to fine tune that FMJ recipe just for the heck of it...

55g FMJBT, H335 powder, 2.225" OAL, range brass. Will be testing 24.7, 25 and 25.3grain loads.

I've got different powders to try and more sophisticated projectiles, but for this first go round, I'm just looking for general purpose ammunition. Any comments or recommendations?

The simplest way I know here is to run an OCW test, find the best group then fine tune seating depth or crimp for even more accuracy. Then crank them out and enjoy.

 

[DLS]

Not to be contrarian but ...

1. You are using a 55gr. FMJBT bullet, which is not very accurate (most are 1.5 - 2 MOA bullets at best).
2. You are using a standard grade rifle which again is not very accurate (again most are over 1 MOA or more average at best when a properly large sample is looked at, not a few cherry-picked 3 or 5 round groups).
3. You are using mixed lot range brass.
4. You are loading for general range use.

By not very accurate I mean that with your bullet and rifle combo you will most likely be very hard pressed to note any real difference in overall accuracy at 100 yards. Especially since you are shooting only a few 3-shot groups. It really takes a minimum of 7 rounds in the group to begin to approach statistical significance regarding true average for group size (American Rifleman and older Speer loading manuals had good articles on this). And that is just approaching significance. To really get a true feel for the rifle takes more shooting.

There is a reason "standard loads" become standard loads. They perform very well across a broad spectrum of firearms. I like H335 for the 5.56 and have used many pounds of it when I was a serious Service Rifle competitor. So, if I was loading for the situation you mention I would simply load 25 grains and test for function.

Now, if you had a match barrel or at least a better chamber profile, were using sorted and prepped brass, and were loading a more accurate bullet my approach would be very, very different.