Load development efficiency

[Jeff Flannery]

Even if we weren't facing a component famine, being efficient with load development has a lot of benefits.

Saving components from unnecessary testing is easy money, and i don't really enjoy shooting over my chronograph, too focused on not hitting it to even care that I'm doing something I love. Then there's the time, planning the groups, making adjustments and verifying. Trying to keep everything organized properly from home, to range and back. Then interpreting the data becomes it's own little 3 ring circus that can lead to a whole lot of nothing useful.

There are lots of methods people use to get the most out of testing. Design of experiments is an incredible concept, testing multiple variables at the same time, wasting minimal resources and still getting good data. Sounds awesome on paper, but getting it to work isn't something I've seen happen very often.

What is your preferred way to develop a new load? What do you look for? Do you decide what you're trying to do first and see what it takes to get there, or do you go through a preset process and let the data tell you what you have to work with? How much data do you need before you're confident enough to start producing? 3 rounds each group, 10, 50 or more? How thorough are you? Do you test every tenth of a grain or skip half a grain or more between groups? Do you test different seating depths at the same time or is it a separate process, if you even do it.

I start by looking at several of my reloading books for a starting place for a load development. I start at the lower end of powder grains and load three of each, working up at 1/2 grain, and being careful not to go over max charge. It never ceases to amaze me how just a 1/2 grain difference can shoot much better.

 

[JFrank]

I modified the Audette ladder test. I can get really good results with about 20 rounds.
Handgun and iron sight rifles get ocw test.

Im interested in your process if you'd care to expand, perhaps an overview of your modifications.

 

[sfl_gunner]

The load development method is dependent upon the goal for the load. If I’m loading for blasting I look for a range of powder variation somewhere on the low end of the powder charges and work up using anywhere between .3-.2 of a grain. Then I shoot 5 round groups and let the paper decide based on accuracy and how well it works the weapon. When developing for my competition I shoot groups of 10 with varying seating depths and powder charges.
Any “waste” is worth it because I know my guns will shoot the loads I’ve tested.

 

[Bfh_auto]

Im interested in your process if you'd care to expand, perhaps an overview of your modifications.

I only look for the higher accuracy node. If it's a rifle I've done load work with. I have a general idea where I get pressure signs vs what the book data says.
In one rifle I know the top half of the recommended charges will cause sticky bolts. So I do a 10 shot ladder from the starting charge to half way up.
In other rifles I know the bottom half of the charge range results in sooty cases.
I figure why waste time shooting through

Im interested in your process if you'd care to expand, perhaps an overview of your modifications.

For initial work up I follow his method to the T.
If I change bullets or powder. I cut the ladder in half.
My heavy 22-250 was giving me pressure signs halfway through.
My light barrel one likes to run about 2 grains over max. I figure there's no point in looking for accuracy where the rifle doesn't give it.

 

[JFrank]

Saved;
Yep I've chased that high node more than once , a good friend tells me they shoot the best just before they shoot the worst.. I tend to believe him too.

 

[Walkalong]

I like @Nature Boy’s method.

 

[JFrank]

Has anyone had success finding a node with a five shot ladder test ?

 

[kmw1954]

Being new to both shooting and reloading bottleneck rounds I do not place a lot of confidence in my own ability to repeat shots, even while firing from a front and rear bag.

So I have been doing 12 shot loading fired in 3 shot groups, 2 groups of 3 on one target and 2 groups of 3 on a second target. I have also been loading in .3gr increments of five loads. After finding which shoots best I load 12 more of that load and increase by .1gr.. So if say 23.1gr shoots very well I will load 12 at 23.2 and 12 at 23.3 as I have already loaded 23.4 and had seen a fall off.

This may be a lot of shooting for some but for me it is also building trigger time and confidence.

 

[WVRJ]

I usually have a bullet in mind when I start thinking about load development.Recently,I pretty much built a rifle around one bullet,and was thrilled when the rifle actually liked that bullet.In these crazy times,I was even more thrilled when I found out that it likes just about every 7MM bullet I've tried in it.
What kind of gun it is,what I want to do with it and what is available for it are a few things that influence how I go about working up a load.In most cases,I do some research if it's a round that I've never worked with before.I read any load data I can find,I check out what guys on this site and a few others have done and then I start to choose components.
I usually try a few of the best powders with the best(on paper)bullet,shooting 3 shot groups at the starting load for each powder.I usually get enough from this to get a start on the next step,which is more 3 shot groups with a gradual increase in charge weight,and maybe I'll start to tinker with overall length a little bit,but I don't put near the emphasis on COAL that I used to most of the time.I like to use bullets that are as forgiving as possible as far as seating depth is concerned.Once I feel like I'm getting something roughed out,the chronograph comes into play.I use to check for abnormally high or low velocity as well as spread.I think it's worth the effort to use one,especially if I want the best accuracy,and I also use velocity readings to help me decide when I'm at the max for that load in that gun.No point in dumping more powder in when it doesn't gain anything more than a bigger muzzle flash.
At this point,I've found a powder type and charge weight that I'm happy with.I've given up on the idea that a tenth of a grain of powder in either direction will give fantastic results.If a load's walking on that razor's edge,I'll keep digging.A change in temperature or elevation can change it enough to make it no better than a more forgiving load.I like to use powders that are less sensitive to temperature change,and I've found some powders that aren't all that popular are very good in this respect,especially some of the Enduron powders from IMR.
Even after I've settled on a load,I'll still keep taking a few rounds of something different with me when I'm shooting just to make sure I haven't missed something.In these times of tight supply,I think it's good to have more than one combination to work with if at all possible.Experience is also very valuable.I have a few 308's,and when I'm starting out with of those,I already have a good idea what's going to work.I don't think there's anything more important than keeping some kind of log on every rifle I have,and some of my customers' rifles as well.I even go so far as to keep the targets themselves to go back and look at.
I can't say that I follow one set in stone regimen for load development,I guess it's more like I have some guidelines that I follow,and I change a little as I feel the need tne thing I do follow is I try to get the most velocity I can without giving up accuracy and/or safety.It would not be good to need a second shot and have a locked up action.

 

[Varminterror]

you plot velocity vs charge weight. This is almost always linear.

This isn’t a real thing either....

Read up on velocity nodes and the Satterlee Method - including the link(s) provided within this thread. Velocity and powder charge are NOT linearly related, the same as pressure and powder charge are not (ya know, that whole pesky physics thing where the integral of pressure curve times the bore area results in a net force, and force = mass x acceleration, and acceleration yields velocity... so pressure and velocity are inherently related... that freshman year physics stuff...)

 

[Varminterror]

Has anyone had success finding a node with a five shot ladder test ?

Finding a node, sure. Defining a node, eh, not so much.

The 24 round blended OCW + Satterlee method I use is triplicate of an 8 shot method.

Starting from nothing, I wouldn’t have faith I could get there within 5-8 rounds, but in redeveloping/correcting a well developed load for a new barrel, I’d be confident knowing I could do it in 5 shots.

The downside: a node really requires 4 shots to be defined - assuming they are the RIGHT 4 shots. If you were lucky enough to shoot one round below the lower bound, two within the node, and one round above the upper bound, and the 5th round anywhere inside or outside, then you have a defined node within 5 shots. But if your selected range touches one side but does not fully envelope the node, then you have only located a node, but not defined its boundaries.

Looking at the pictures linked above as examples: the 107 SMK target appears to have a node which includes charges 4 and 5, but we don’t know the upper bound of the node. Equally, in the 108 ELD target, charges 1, 2, and 3 are clustered together, but we don’t know the lower bound of the node.

*I shoot in triplicate to help ensure the ~1/8-1/4” difference in POI is meaningful. Considering a cone of dispersion, if that 107SMK target, if #3 is the low strike of its cone, #4 a high strike, and #5 a low strike, then the centroids of GROUPS fired at those charges might have placed 3 & 4 level instead of 4 & 5. It’s also why I don’t like to shoot POI based load development at short range - I prefer to get out far enough where load dispersion starts catching and exceeding my mechanical dispersion as the shooter.

 

[JFrank]

Y'all should listen to @Varminterror more often.

He is 100% correct as I'm not showing the outer limits on these two examples' I cheat... Actually I work with 6BR quite a bit so I know there is a "high node" on the 107 SMK target I thought I had (LOST MY WAY ) when that happens i always fall back to double check my combustion first in this case a quick ladder confirms 30.1 and held up at 550 shooting 5 under 1 inch group. Any further breaks out of the quadrant.
The Berger 108 quick test the cluster of shots 123 looked great at 200 then opened up at 550 until I added more powder (30 gr put 3 shots under 1 inch again.
I still use an incremental ladder for locating course powder charge accuracy area but find that coloring the ogive of three(or more) of each and shooting at one point of aim at distance reduces variables , speeds up the process and is a very true representation of the load im developing or confirming weather powder, seating or neck tension. Depending on the level of tune required I can get there fairly quick.
There are lots of styles and methods to choose from I don't think any are wrong some are just different.

 

[Walkalong]

I used, let's see, 19, then 27, to sight back in, and then just tweak a load for a new lot of powder, so 46, but I also tried a different brand of brass, so I could subtract 6 & 10 for that, for 16, so 30 for just tweaking the load in the same brass with the same bullet/primer due to a new lot of powder.

And if starting from scratch, I would have used more than 30, because my initial run of three shots each would have been a wider band. I don't trust one shot each.

So, if you ran a "ladder" from say 32.0 to 33.0 in .2 increments, with one shot each, called a flat spot and went with it, I doubt you have the best load, serviceable maybe, but not the best.

*I shoot in triplicate to help ensure

Repeatabilty.

My numbers here are five shots, but they repeated what the three shot test gave me.
They are laid out/charted differently than VTs, but give the same info.

From Page 1.

Between the three shots results and then these five shot results where the small SD numbers repeated them selves in
the same spot, I can load 32.3 in Lapua cases and 32.2 in Alpha cases and be confident it will be flat shooting at distance.
It is still shooting small groups, when I don't screw it up, and not bad when I did, so any misses laterally are me misreading wind.

But the small SD numbers mean they will be flat shooting at distance, so if my dope is right, repeated hits are more probable.

 

[Coyote conquest]

I use to do the whole start at the lowest charge and work my way up .2 or .5 of a grain at a time depending how much powder the case holds. I'd go all the way to max, Then verify the results
Somewhere along the line I figured out that I can search the net and find other people who shoot the same powder in the same cartridge and start with their loads and be close to a great load.
I'm sure I can't be the only one. Look at how many people shoot around 60gr of H4831 with 130gr bullet in .270. or between 25 and 25.5 gr of H335 with a 55gr bullet in 556.
It's because the loads just plain work in most rifles. Not always but if that wasn't true you wouldn't have match ammo that shoots so good in so many different rifles.
Doing that comes in really handy during the shortage right now to save components.

 

[kmw1954]

I use to do the whole start at the lowest charge and work my way up .2 or .5 of a grain at a time depending how much powder the case holds. I'd go all the way to max, Then verify the results
Somewhere along the line I figured out that I can search the net and find other people who shoot the same powder in the same cartridge and start with their loads and be close to a great load.

I can understand that line of reasoning yet for me I am still learning and need to go thru the whole routine for the learning experience. Start with a load and work up, in my case 12 each in .3gr powder increases. I'll load 5 loads and then shoot them in four groups of three onto 2 separate targets. I'll then load the next batch which I am working on presently. This gives me both the experience in developing the load and the trigger time shooting the loads. I have noticed that this has also forced me to slow down my shooting tempo and concentrate harder on each shot.

Last time out I shot 60 rounds in about 2.5 hours. But then that was also at my home range were they shoot in 15min. cycles. During cease-fires I would go down and inspect my target.

 

[noylj]

It can work, but you are assuming that your mix of powder lot, bullet shape/brand/lot, primer brand/lot, and even internal case capacity will not produce a dangerous tolerance stack. I would rather only fire one round and work up, then ASSUME that everything will be OK.

 

[kmw1954]

It can work, but, ----------, will not produce a dangerous tolerance stack. I would rather only fire one round and work up, then ASSUME that everything will be OK.

Exactly but just remember that Tolerance Stacking can and does go in both directions and to both extremes.
So I don't follow how one of anythings proves or disproves an outcome.

 

[Bfh_auto]

Being new to both shooting and reloading bottleneck rounds I do not place a lot of confidence in my own ability to repeat shots, even while firing from a front and rear bag.

So I have been doing 12 shot loading fired in 3 shot groups, 2 groups of 3 on one target and 2 groups of 3 on a second target. I have also been loading in .3gr increments of five loads. After finding which shoots best I load 12 more of that load and increase by .1gr.. So if say 23.1gr shoots very well I will load 12 at 23.2 and 12 at 23.3 as I have already loaded 23.4 and had seen a fall off.

This may be a lot of shooting for some but for me it is also building trigger time and confidence.

That's how I used to do it. It definitely helped me see trends and the extra shooting was a huge bonus.
Since each shot was part of load development I couldn't slack off.

 

[Bfh_auto]

Has anyone had success finding a node with a five shot ladder test ?

That looks like confirming a node is where you think it should be.
That's similar to what I was talking about earlier. Save the bullets for fine tuning instead of eating them on the charge range it won't like anyway.