How many rounds for load development?

[P7M13]

I shake my head at my methodology that I used when I started loading for distance work. I'd do OCW and chrony at the same time (Chrony Beta Master), but the charges I'd pick made no sense.
Then I moved to five shot strings of each charge weight for OCW. Then dropped it to three per string. I still do three shot strings.
I'll also load 10-14 rounds of a powder range (min to above book max) and find a node using chrony data. Then load three shot strings in that node separated by .2 - .3gr in charge weight.

Things that have surprised me:

• On multiple rifles, above published max has been the best, most accurate round. While some writer once said that the same MV / bullet / weight from a rifle will yield the same accuracy results using different powders, I find different powders behave *very* differently, even with similar MVs.
• In the "nodes" I've selected, sometimes the charge weight variation makes almost no difference in the accuracy -- telling me it's a good node. There, seating depth and my practice make the difference.

ETA - good point by @DLS. I once asked a buddy of mine who is 10x the shooter that I am about load development for the AR. He replied, "I just load those up, they're only cover fire."

 

[Catfishmoon]

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.

I agree with Wombatz...
If using a chrono in your situation is possible, I would certainly use one, more information is always beneficial...
I do most of my shooting at ranges where a chrono cannot be setup and used, henceforth I have never bought one..

 

[Hooyah DeepSea]

Yeah, what I said . . .

 

[DLS]

I'll also load 10-14 rounds of a powder range (min to above book max) and find a node using chrony data. ...

This, in short, is how I do load development on accurate rifle / component combos.

the "nodes" I've selected, sometimes the charge weight variation makes almost no difference in the accuracy -- telling me it's a good node. There, seating depth and my practice make the difference.

Once you find a good node, you can greatly speed up the loading process since you don't need to be weighing every powder charge to the gnat's behind.

 

[jkor]

The node is a area where velocity does not change much, correct? Like, 20gr, 20.5, 21, with virtually no velocity change?

 

[DLS]

The node is a area where velocity does not change much, correct? Like, 20gr, 20.5, 21, with virtually no velocity change?

Yep, exactly!

Once you find a good node, set your powder measure to the middle of the range and load away. So, you can get match grade loads on a progressive machine unless your node is extremely small in range ... but then is it really a node anyway?

Some of the most accurate ammo in the world is loaded on progressive machines using this technique, saving a ton of time and frustration.

 

[Ben B.]

This is the best video (really a podcast) on reloading I've seen. It is data driven, with LARGE samples. It is long, great for listening on a drive. Sacred cows do get gored. See if you agree….

 

[dangerranger60]

When making a plinking load, I am more looking for the cheapest bullet and least amount of powder that gives decent accuracy. Ladder tests very rarely get me there. But the Chrono gives me good InSite into bullet/load combos that have a low velocity difference shot to shot. That and the target give me what I need to make up a good plinking load. DR

 

[DizzyJ]

I start midway through the load range and load to one or two charges above max listed charge. Stop when you start seeing pressure signs.

I load 4 rounds at each powder charge weight (3 for an initial group with a "spare" I'm case I feel I pulled one of the shots).

Evaluate what the target tells me then go back with 5 loaded up for each group that looked "promising". Usually you'll find two decent groups from the initial work up.

Evaluate what the 2nd test tells you (using 5-rounds per powder charge).

Figure out which final load you like the best.

Proof it with three five shot groups of the same load.

For .233 I vary the charge by 0.3grains

For 308 and similar case capacity cartridges I vary the load by 0.5grains.

From there you can either step down to smaller powder charge increments, play with bullet seating depth or call it good.

I also shoot my groups round robin in order to evenly disperse variables such as barrel heating up, etc.

Chrono is my last step to verify velocity.

 

[Tikka308]

10

 

[orygun]

@P7M13 , OCW?

So far the cartridge that I've spent the most time on has been 30-06 AI.
I vary weights by .5gr. I found the lands and backed off a little, .020". Since I found an accurate load I never varied the bullet seating depth. Must have gotten lucky.

 

[Spitpatch]

Ammo for "general range use, plinking and running drills" requires very little "load development", and I would agree with those who postulated purposing economical factory or military ammunition for such. Efforts toward ladder testing, chronographing and logging of data should be reserved for more specialized applications (unless you have all the time in the world and simply enjoy the process, of course.)

The 25.0gr H335/55gr load I came by the hard way (extensive testing) rather than "reading about it" or "recognizing a standard". In that regard, focusing on this recipe is an awfully good start. It is beneath max, easy on brass, safe in any gun, and operates autos flawlessly...and is accurate. My .223 guns are nearly all fed this recipe now, even though I am a firm believer in dedicated brass lots for each gun with respect for chamber dimensions, seating depth and the like. The one exception is a fat-barreled 700BDL that noticeably benefits (with measurable results) from a more finely tailored load. When I owned a 14" .223 Contender barrel, a different recipe for that was understandably required. (I rather quickly got rid of that barrel: a Fireball makes infinitely more sense in a handgun.)

As to group sizes for testing, I utilize group sizes according to the application of the gun. A Prairie Dog rifle must produce 10-shot groups of hard consistency from a barrel that is warm and getting warmer. A bolt-action big game rifle must produce 3-5 shot groups that are consistent in relatively rapid fire, starting with a barrel stone cold. A single shot big game gun demonstrates its consistency reliably with 3-shot groups. It will almost never be asked to do more in the field. A "range gun" that may never see the hunting fields only needs a load that never becomes the reason for an off-target miss. This is a pretty easy bar to meet.

Utilizing a consistent target face, groups of only a few shots can be superimposed over each other should one wonder how his Sharps .45-70 drops seven or ten bullets onto a piece of paper (with the added benefit of not having to poke that mule in the butt that many times in a row).

No testing procedure is a blanket application for guns of varied usage.

 

[Pepe-lepew]

OP is talking H335 and bulk 55's. No need for load development. Just load up the standard load already mentioned and run with it.

 

[jkor]

This is the best video (really a podcast) on reloading I've seen. It is data driven, with LARGE samples. It is long, great for listening on a drive. Sacred cows do get gored. See if you agree….

Going to have to watch that. I listen to their podcast but, video would help.

 

[PiratePast40]

Lots of good methods and suggestions here. Even though 25g seems to be the standard load, I just wouldn't feel right unless I tested a few before cranking out a thousand. Will do 10 each at 24.7, 25, and 25.3. Run 5 each over the chrono with a target at 20 or so yards and then over to the main range with the remaining 5 each to see if there is any difference.

Will do the same with CFE 223 but at 24.5, 25 and 25.5. I have 3 pounds of each and both are easy to find. I read about the OCW method and the shooting order makes sense.

For Christmas, I received some new Starline brass and some 53 grain Hornady ELD match bullets. Will play with those at a later date, but to be honest, not sure my Faxon Gunner barrel will do them justice. Will most likely save those for prairie dogs.

 

[Koda]

Run 5 each over the chrono with a target at 20 or so yards and then over to the main range with the remaining 5 each to see if there is any difference.

If you can squeeze at least 50yds you can get a better idea of group size nodes at the same time your gathering velocity data.
and zero the AR at the same time.

 

[Certaindeaf]

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.

Shoot them all at 100 for accuracy and function. I'd probably do 5 shots each.

 

[arrowshooter]

Have fun exploring. And just so you know, there is no cure for this addiction. I struggled for years with not "experimenting" with different components and found that to ease the pain I just added calibers. That's just me and my own OCD though.

You may want to reconsider your ladder with the CFE223:

BULLET WEIGHT
55 GR. SPR SP
CASE
WINCHESTER
PRIMER
WINCHESTER SR, SMALL RIFLE

	Starting Load		Maximum Loads
	Manufacturer	Powder		Bullet Diam.	C.O.L		Grs.	Vel. (ft/s)	Pressure		Grs.	Vel. (ft/s)	Pressure
	Hodgdon	CFE 223	BUY NOW	0.224"	2.200"		26.0	3,133	43,300 PSI		27.8	3,329	51,300 PSI
	Hodgdon	H335	BUY NOW	0.224"	2.200"		23.0	3,018	40,800 CUP		25.3	3,203	49,300 CUP

 

[P7M13]

@orygun ,
OCW, (Optimal Charge Weight) as I know it, is shooting groups of different charges to determine best, most accurate load.

Another observation over decades of reloading : loads are a combination of the powder, bullet, gun and shooter. The example I think of is one where I had one load with single digit ES/SD for one load, but another load which had a ES >14 and was consistently more accurate in my hands.

Hence, I'll use a chrony to determine the node(s), and then shoot groups within that node to see which one works best for me.

I try to do my testing at 200 yards whenever I can.

If you've ever practiced yoga, you've probably heard the joke, "when you're life is out of balance, your balance is out of whack." Same holds for shooting. Some days, can't slow anything down and thus shoot like shizzle.

 

[Ben B.]

Interesting conclusions from the Hornady podcast report

1. If you shoot enough rounds for statistical relevance, there is no accuracy difference (or minimal) between book minimum and book maximum charges.

2. All of the sinusoidal "nodes" discussed vanish if you fire enough rounds. The nodes are an artifact of low sampling error.

3. Powder choice makes the biggest difference.

4. Bullet makes the second biggest difference.

5. You can find good loads using the classic methods.

6. Zeroing should be done on 20 round groups. Otherwise, you may incorrectly center your crosshairs out of the "true" center point of dispersion. This explains some wandering zero/change in zero.