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Ladder test

I would like to understand that better myself. Seems like everytime someone starts to tell how it's done several others start in adding to or changing things up till I get lost trying to understand the steps in order. I would like to see it in numbered steps simply explained. Something like ladder testing for dummies. Step#1, step#2 and so on.
Farmerjohn
 
You shoot in increasing increments and see where you have similar points of impacts. This is the first result when I google "Ladder test" and it should say pretty much all there is to say about the matter http://www.6mmbr.com/laddertest.html

And with zero words
baneylad00.png
 
I only clicked this to see what Spife7980 had to say about ladder test, in the hopes that somebody could understand this simplest of tests (thank you, Creighton Audette). Bravo! This is it; this is all there is.
 
Okay, in terms that even Tommy can understand. Load 21 round in 1/2 grain increments. Assuming you have an idea of what a proper load would be, 3- 1/2 grain intervals above and 3- 1/2 grain intervals below that ideal level. On a rather large sheet of paper draw an horizontal line. In even spacing across that line draw seven vertical lines. Place that "target" on a frame 100 yards out. Also load two rounds for barrel foulers. Fire the two foulers any old place. Hold on the horizontal line for all shots and proceed from left to right and shoot three shots at each of the seven crosses with each of the seven loads from coldest to hottest load. You should now have seven sort of decent groups. Plot a line through the center of each group and follow the dots. You should now have a sine wave or wavy line. Your best loads should be just before a high point in the wave and just after a low point in the wave. Easy Peasy

Oh, I see, two others answered while I was typing.
 
This is how I do it.
I shoot F class using single shot actions so magazine length rounds are not a factor. I also use what I call a “caliber rule.” For instance if the caliber is .2xx I use .2gr increase in powder charge, if it’s .3xx I use .3 increase in powder.

Bullet seating depth for initial testing will depend on the type of bullet. VLD vs other types. Usually I start with a dummy round (sized case without primer or powder) loaded long. I try it in the chamber if the bolt won’t close I extract it and seat the bullet deeper in the case. Repeat until the bolt closes and I can extract the round and not leave the bullet in the neck.

Powder charge: I use a charge that is only 80% of the listed max charge for that bullet. Write the charge weight on the case with sharpie marker. Load one round at each increasing powder charge on the case increasing the powder X amount per round. It will take 20-30 rounds.

Testing: testing is best done at the range you want to shoot, 600yds, 1K. Unfortunately not everyone has access to these ranges. I use 300yds. I don’t test at 100yds. Eric Cortina did an excellent write up on 100yd testing you can search for it here. I use two targets. One to shoot at and one on the bench for plotting. I start with the lowest powder charge and use the same point of aim for all rounds. Fire the round and plot it on my bench target. Like #1 XX powder, #2 XX powder etc. if I get to a point where bolt lift is hard or I get bolt “click” I stop. You’ve hit your max charge.

What I’m looking for: these rounds will not be the most accurate ones. You will see as the powder charge increases the POI will move. What you will see is a range in powder charge that is pretty much in a horozontal line. Let’s say from 40- 40.5 this is what your rifle likes. For the next range session load in the middle 40.3.

Bullet seating test: from the original OAL seat 3 bullets .005 deeper in the case. Repeated seating in .005 increments. You will find a seating depth where groups really tighten up. Next you can adjust seating depths in .001-.002 increments on either side of your best groups. Once you have determined what’s best in your rifle repeat this test using 10 shot groups.

Hope this helps. Others may have different methods but this works.
 
Google ladder testing, and look for a hit at sierra bullets. I followed this posting for the most part but I only have 200 yds distance.
 
I use and advocate a modified ladder. Dont think of it as a ladder. Test anything you want. Just load 3 shot groups and shoot them all at the same poa fast. Lots of data to gather. Color bullets so you can identify them. I do it at 1k and even the light hunting rifles get the same treatment.
 
Google ladder testing, and look for a hit at sierra bullets. I followed this posting for the most part but I only have 200 yds distance.
Just did the test today using the Sierra methodology at 300yds using the 195TMK and 200 Hybrids. The 200hybrids was ~2” of vertical at 300yds unfortunately I can't push it out further to test. But I think i got a good enough data to proceed with the next steps.
IMG_20180601_170438356_2.jpg
IMG_20180601_170522662_2.jpg

 
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GROUP shooting is not a ladder.
Okay, in terms that even Tommy can understand. Load 21 round in 1/2 grain increments. Assuming you have an idea of what a proper load would be, 3- 1/2 grain intervals above and 3- 1/2 grain intervals below that ideal level. On a rather large sheet of paper draw an horizontal line. In even spacing across that line draw seven vertical lines. Place that "target" on a frame 100 yards out. Also load two rounds for barrel foulers. Fire the two foulers any old place. Hold on the horizontal line for all shots and proceed from left to right and shoot three shots at each of the seven crosses with each of the seven loads from coldest to hottest load. You should now have seven sort of decent groups. Plot a line through the center of each group and follow the dots. You should now have a sine wave or wavy line. Your best loads should be just before a high point in the wave and just after a low point in the wave. Easy Peasy

Oh, I see, two others answered while I was typing.
 
for charge steps, 1/100 of case volume.
.3 in a 30 br is no where near .3 in a 300 win mag
just an idea from the guy that popularized ladder testing.
This is how I do it.
I shoot F class using single shot actions so magazine length rounds are not a factor. I also use what I call a “caliber rule.” For instance if the caliber is .2xx I use .2gr increase in powder charge, if it’s .3xx I use .3 increase in powder.

Bullet seating depth for initial testing will depend on the type of bullet. VLD vs other types. Usually I start with a dummy round (sized case without primer or powder) loaded long. I try it in the chamber if the bolt won’t close I extract it and seat the bullet deeper in the case. Repeat until the bolt closes and I can extract the round and not leave the bullet in the neck.

Powder charge: I use a charge that is only 80% of the listed max charge for that bullet. Write the charge weight on the case with sharpie marker. Load one round at each increasing powder charge on the case increasing the powder X amount per round. It will take 20-30 rounds.

Testing: testing is best done at the range you want to shoot, 600yds, 1K. Unfortunately not everyone has access to these ranges. I use 300yds. I don’t test at 100yds. Eric Cortina did an excellent write up on 100yd testing you can search for it here. I use two targets. One to shoot at and one on the bench for plotting. I start with the lowest powder charge and use the same point of aim for all rounds. Fire the round and plot it on my bench target. Like #1 XX powder, #2 XX powder etc. if I get to a point where bolt lift is hard or I get bolt “click” I stop. You’ve hit your max charge.

What I’m looking for: these rounds will not be the most accurate ones. You will see as the powder charge increases the POI will move. What you will see is a range in powder charge that is pretty much in a horozontal line. Let’s say from 40- 40.5 this is what your rifle likes. For the next range session load in the middle 40.3.

Bullet seating test: from the original OAL seat 3 bullets .005 deeper in the case. Repeated seating in .005 increments. You will find a seating depth where groups really tighten up. Next you can adjust seating depths in .001-.002 increments on either side of your best groups. Once you have determined what’s best in your rifle repeat this test using 10 shot groups.

Hope this helps. Others may have different methods but this works.
 
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To save time reading, learning, and crossing my fingers, i developed my own system based off how I interpreted the point; control the variables and change 1 at a time in logical order. I just loaded 4 rounds .015 off lands (depends on bullet)per charge weight in small increments as step 1. Step 2 I loaded in .1gr increments for top 3 most accurate charge areas. Once I shoot those I’ll have the best charge weight for that set. At that point I will probably have 2 accurate charges and will then try different brass, primers, seating depth. I will continue with several bullet/powder combos. I just started shooting a couple months ago and my step 1 yielded a .46 and .214 Ctc so far, not even shot step 2 yet. However I am under 100 yds a little but take accurate crony numbers and notes, I’ll shoot all my load development at the same spot so the exact 100yd don’t matter imo. I shoot a Bergara b14 270 win
 
again , if you start with GROUPS, you are not shooting a LADDER.
I DON'T say it will not work, it is just not a ladder, and this thread is about LADDER, not generic load development.
To save time reading, learning, and crossing my fingers, i developed my own system based off how I interpreted the point; control the variables and change 1 at a time in logical order. I just loaded 4 rounds .015 off lands (depends on bullet)per charge weight in small increments as step 1. Step 2 I loaded in .1gr increments for top 3 most accurate charge areas. Once I shoot those I’ll have the best charge weight for that set. At that point I will probably have 2 accurate charges and will then try different brass, primers, seating depth. I will continue with several bullet/powder combos. I just started shooting a couple months ago and my step 1 yielded a .46 and .214 Ctc so far, not even shot step 2 yet. However I am under 100 yds a little but take accurate crony numbers and notes, I’ll shoot all my load development at the same spot so the exact 100yd don’t matter imo. I shoot a Bergara b14 270 win
 
again , if you start with GROUPS, you are not shooting a LADDER.
I DON'T say it will not work, it is just not a ladder, and this thread is about LADDER, not generic load development.

Noted. ... it’s late. I made an unconscious judgement call between what the op was specifically wanting vs what I wanted to talk about. My Mistake. Its bothersome when it happens to me to.
 
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