The ladder method of development.

[John O.]

In my studies on load development I have read that it is advisable to either raise or lower the powder charge by half of a grain. However recently I watched a video on you tube and fortune cookie 45lc's method it to adjust the charge in three tenths of a grain with great affect. I know that as long as you do not go over the max charge you will have no problems. I was just wondering what are the advantages to disadvantages of each system. I believe with the three tenths you may use up more powder initially. however when your group tightens up you have less of a gap between each charge to fine tune the load.

 

[Alex Wheeler]

Its best to use a percentage. I use 1% increments for roughing in, then go to .1 increments to fine tune.

 

['Freak]

I increment up adding onto the previous charge weight, 0.85% to 1.0% of the listed maximum.

 

[Brians356]

I increment up adding onto the previous charge weight, 0.85% to 1.0% of the listed maximum.

But ... what does the specific charge change increment have to do with "The ladder method of development" in particular?

 

[Terry]

If the steps are too far apart you might miss one.

 

[John O.]

In response. I have read in my reloading manual and on this forum that in development of a load. It is advisable to either raise or lower the powder charge by .5 grains per test. However in watching some of the a fore mentioned you tuber's videos he raises or lowers his powder charge by .3 grains per test load. I was wondering what are the advantages and disadvantages of each.

 

[noload]

The closer the charges are the more powder, bullets, etc, and reloading time, but the better results. The larger the powder gap between charges the more inconclusive the test, and will require more testing. Your choice.

 

[LRPV]

Its best to use a percentage. I use 1% increments for roughing in, then go to .1 increments to fine tune.

1% of charge weight or case volume Alex?

I go up in increments depending on case volume I guess. For BR/dasher cases .2 grains. 22-250/243 .3 grains. 284, .4 grains etc. Then I'll fine tune it more after I find something I like.

 

[John O.]

Ok i get what you are saying about using a percentage of case capasity. Wthat is 1# of a 25-06 case?

 

[LRPV]

I guess my way figures out to be around .5% of the water capacity of a case. 25-06 is around 65 grains of water. So, .3 grain increments is what I would do. Might not sound like much difference but steps this small should not get you severely over pressure from one to the next when you get towards the upper limits of pressure either.

 

[CharlieNC]

Increments of 0.1gr would give excellent node definition ; obviously more work and cost but the results would be clear.

 

[John O.]

Thank you LRPV forexplaining it sufficently. As well as every one else who helped..

 

[John O.]

Re: The ladder method of de of a velopment.

Increments of 0.1gr would give excellent node definition ; obviously more work and cost but the results would be clear.

Yes I do intend to eventually trickle powder in at a tenth of a grain when after I get one moa at the rough stages of development. From thence I will really make my rifle and load combination sing, as targets get hit or dropped.

 

[Mozella]

You can also throw in the question of five shot groups vs three shot groups. I always shoot 5 shot groups during load development, but plenty of folks prefer to start with 3 shot groups.

I also always measure my loads in percent of published maximum. Where more than one maximum is published, I pick one and mark it on my master load sheet and work from that data point. I find it hard to remember if 27.9 gr of IMR 8208 XBR is a hot load or not, and what might be a mild load for my 6mm BR Norma, might be a hot load for my .223 Rem................. or not. I work with so many combinations of powder bullet weights, and charge weights I just can't keep track of them all. But by using a percentage to describe a load makes sense to what's left of my brain.

For example, if I have a particularly accurate recipe using 94% of Max, then I know it's a relatively mild load. Likewise a 108% load is a little bit hot. And that has significant meaning for me when working up a load or when out shooting a proven accurate recipe.

Of course I have to consult my data when I prepare to load a batch of rounds to be sure I know how many grains of a certain powder 94% represents, but I do that anyway and always double check my data.

 

[LRPV]

Re: The ladder method of de of a velopment.

Increments of 0.1gr would give excellent node definition ; obviously more work and cost but the results would be clear.

Yes I do intend to eventually trickle powder in at a tenth of a grain when after I get one moa at the rough stages of development. From thence I will really make my rifle and load combination sing, as targets get hit or dropped.

Don't confuse ladder testing with just loading up a few charge weights, throwing them at some paper to see if anything sticks. Here is a rather lengthy article but it explains the ins and outs of working up a load with the ladder method.
http://www.accurateshooter.com/technical-articles/long-range-load-development/

 

[CharlieNC]

There is no magic in the various approaches aimed at finding a node. Most important is understanding the principle and designing the evaluation procedure to best assure you can clearly find the node, i.e. separate the signal from the noise. Finer increments require fewer shots per load because there will be more neighboring charges that will indicate a given node, which is better differentiation than more shots at more widely spaced intervals which could obviously miss finding nodes all together. The primary unknown is how much noise you have; if there is overbearing wind, or you can't hit a bull in the ads, then there will be problems finding a node.

 

[Alex Wheeler]

Its best to use a percentage. I use 1% increments for roughing in, then go to .1 increments to fine tune.

1% of charge weight or case volume Alex?

I go up in increments depending on case volume I guess. For BR/dasher cases .2 grains. 22-250/243 .3 grains. 284, .4 grains etc. Then I'll fine tune it more after I find something I like.

A dasher case will max around 33-34 grains of rl 14. 1% of that is about .3 grains. That would be a very rough ladder to tell you where to look. At that point I would do another in .1 increments to find the right spot. Same thing on a bigger case. Dont let them fool you with this wide node stuff. If you want you gun to shoot its best you have to be on it, not .1 either way. At 1k, there are no wide nodes in my experience.

 

[LRPV]

There is no magic in the various approaches aimed at finding a node. Most important is understanding the principle and designing the evaluation procedure to best assure you can clearly find the node, i.e. separate the signal from the noise. Finer increments require fewer shots per load because there will be more neighboring charges that will indicate a given node, which is better differentiation than more shots at more widely spaced intervals which could obviously miss finding nodes all together. The primary unknown is how much noise you have; if there is overbearing wind, or you can't hit a bull in the ads, then there will be problems finding a node.

Well said.

 

[Webster]

Usually .3 increments for small cases and .5 for bigger cases. 1%.