Ladder Method?

J300UM

Beginner
Aug 14, 2006
87
0
I didnt want to steal KOA's thread to ask this but has anyone here used this method of load developement? I keep reading about it on another website but I dont want to ask anyone there about it. It seems that every question there is a stupid one and they'll let you know how stupid it was. Anyway, I was just curious if anyone has used this method and how it worked out for you.
 
I don't use the ladder method exactly, but think that you can look at the point of it as a way of developing a load any way that you want. ie: I make up 3 loads of each powder charge and shoot one group at a time at targets lined up next to each other. I can often see the relation to where groups are printing on each target arranged horizontally, and find the loads that print to the same POI, and determine that to be a good load area to foucus on. I also get to analyze the three shot groups as well. If you don't follow, I can further explain. It seems to be a good way to optimize analysis for me.
 
I use what I call "ladder loads". I will start out with a starting load and load five rounds all at the same C.O.L. in .5 grain increments. I will shoot five shot groups and the load that gave me the best group will be the load I work around. Sometimes I'm happy with that load sometimes I move up or down .3 grain and change the C.O.L. Has worked for me so far.
 
I have used it several times and it does work. I am just stuck on my old ways of doing things.
 
Often times when I'm trying to establish my max pressures I'll load up 2 per powder charge, and shoot the string. Why didn't it ever occure to me the also use that to establish my starting accuracy point? Probably because I'm too much of a speed freak and always focusing on the top loads.
 
How to shoot a ladder

I’m going to give an example of how I shoot ladders for my 30-06 Ackley Improved. I had it rebarreled in November 2006 to the Ackley chamber. I’ve since shot at least ½ dozen ladders through it and have found several sub MOA loads. The most recent was with the 200 gr Nosler Partition and H1000. I will address the fact that I do push my pressures quite a bit higher than SAAMI, though a SAAMI standard does not exist for the Ackley. I’m going as high as an estimated 65,000 psi obtained via QuickLoad which allows up to 69.7 gr for an estimated 2899 fps from my 26” barrel. Most people can’t even begin to believe you can get 69 grains of anything into a 30-06 AI case; you can actually get up to 71 grains in via a slow trickle through a long drop tube followed by lots of powder compression via bullet seating. Works for me the proof is in the pudding which I can provide.

First off determine you range of powder charges. My max is 69.7 gr thus subtract 8% to 10% we get roughly 5.5 to 7 grains which gives a minimum charge of 62.7 to 64.2 grains of H1000.

I use an EXCEL spread sheet to keep track of things, entering one piece of info into each cell. Starting w/ the 69.7 gr, reduce each load by .3 gr. Thusly

63.7
64
64.3
64.6
64.9
65.2
65.5
65.8
66.1
66.4
66.7
67
67.3
67.6
67.9
68.2
68.5
68.8
69.1
69.4
69.7

You’ll notice there are 21 individual loads which puts my minimum between the 8% to 10% minimum charge. You can do more or less, your choice. Now load up one shell with your chosen case, primer, bullet combination, with only ONE each of the above powder charges. Make sure they are all identical except the powder charge. The powder charge is the only variable you want.

Now, load up 5-6 extra loads some around the 65 to 66 grains to use as fouling/sighting shots.

Go to the range to shoot on a day where the weather is VERY calm. My favorite spot usually has the sun behind me, wind usually from my front or back and has 300 yds available. I use www.weather.com to check the hourly weather report to see if a certain day will be conducive to shooting a ladder. I also like the winter time for shooting ladders as the temps are colder, which helps to keep the barrel cooler. Other wise you may be there for quite a while, waiting for your barrel to cool between shots. This leads to potential weather changes which are not good for the group you will be shooting. It’s important to shoot these at 300 yds or more. You’ll understand in a bit. Set up a large clean, white (easier to see the bullet holes from 300 yds), target backer with no bullet holes in it at 100 yds and shoot several of the spotter/fouling shots to make sure you’re “on”. Not all of them, just enough to make sure you’re where you need to be. Now back your target out to 300 yds. You’ll want a scope powerful enough to easily see the aiming spot at 300 yds. I’ve done it with a 4x scope but it is much easier at 9x or more. I currently use my 14x setting on my 4.5-14x50 Mk4 and would use even more if I had it. You’re basically shooting one large group at 300 yds and want to take out all possible shooting errors. Shoot from a very solid bench, not over your truck hood or the ground if you’re going to use a chronograph which is highly advisable. For my 14x I draw a simple 2” square with a black magic marker. Set up your chronograph, get totally set up and shoot the last of the fouling/spotter rounds to make sure you’re on the paper. Make the necessary scope adjustments to hit closer to the aiming spot. It’s not necessary to get centered, just close. Now, start shooting your ladder, starting with the lowest powder charge. Shoot it and mark on a clean piece of paper where the hit occurred in relation to the aiming spot. There are several ways to do this. It’s best to have a good spotting scope to see the hits but either your spotting scope is not up the task, as my old Bushnell Trophy isn’t on hot, mirage filled days, or it is on a cold, clear day and sun is from my back. Other methods are to have a friend down range in a safe area, run to the target after each shot and mark the holes 1 through 21. Another is to set up a video camera a few feet in front of and to the side of the target to video the whole group forming sequence and the last is to drive (preferred) or walk/run down to the target after each shot. I’ve done this during the winter when their was too much snow to drive down to the target for each shot and the video camera batteries would die out (due to the cold) after only about 10 shots.

Also write down the velocity next to each shot #.

63.7 2668
64 2679
64.3 2683
64.6 2691
64.9 2701
65.2 2714
65.5 2728
65.8 2741
66.1 2754
66.4 2733
66.7 2777
67 2774
67.3 2790
67.6 2815
67.9 2821
68.2 2845
68.5 2845
68.8 2858
69.1 2863
69.4 2876
69.7 2881


As you are shooting and marking down which shots land where in relation to the aiming spot, you will see a pattern, which usually climbs; not always. Mine usually climb and go to the right. Probably my less than stellar bench technique. Once you’ve got your 21 holes in the target and you know precisely which one is which, i.e. 1 through 21, it’s time to pack up and go home to figure out what you have.

What you are looking for are groups of sequentially grouped holes. Some holes will be all over the place and some will group closer to the numbered bullet holes in sequence. Example, holes 1, 2, 3 are all other place. Holes 4, 5, 6 are clumped together. That would be a node or sweet spot. Holes 7 through 12 are, again, all over the place or not even close to each other. Then holes 13, 14, 15, 16, are, again, close. Finally 17 through 21 are spaced out. You’ve got two decent nodes to focus on the next time you go to the range.

Now, try shooting a ladder at 100 yds, I did it once and will only do it once, and you will have holes so closely spaced you will have a hard telling which are nodes and which are not. Shoot your ladder at 300 yds.

My 200 gr Partition ladder took 21 shots plus 4 shots for the fouling/sighter shots. I focused around one node at 68.5 gr which cost me another 12 rounds (two 6-shot groups). I settled on 68.4 grains. I then tweeked the seating depth by shooting six 5-shot groups, each at .005” difference in seating depth. I started with the first group touching the lands (I also use that for my ladders), then worked my way out, away from the lands, ending .025” off the lands. I settled on .020” off the lands. So that’s another 30 shots. Sixty seven rounds total and I have a 10-shot, 300 yd group which ran 2.87”, 26 ES, 2854 fps average and an SD of 8.

I’m still undecided if I will try a primer test where I might try a Fed 215M primer since I packing over 60 gr of a magnum level (H1000) powder. Who knows, with another 10 rounds I might have a load which exceed the afore mentioned results

I’m tired of typing.
 
GSSP

Great write up, thanks for taking the time to spell out "Ladder Test 101".
Your method will identify the 2 sweet spots that every rifle is supposed to have. Much better approach than the hit or miss method I have always used.

As an FYI, my smith advised me to switch to the GM215M in my 280 AI and my accuracy greatly improved.

JD338
 
Antelope_Sniper":1czttn8s said:
Often times when I'm trying to establish my max pressures I'll load up 2 per powder charge, and shoot the string. Why didn't it ever occure to me the also use that to establish my starting accuracy point? Probably because I'm too much of a speed freak and always focusing on the top loads.

This is where forums like this help out!!!!!!!!!! :mrgreen:
 
J300UM great question! This is something similar to what I was looking for in my earlier post; I guess I just need to learn how to ask better questions. Thanks for the consideration by the way. It's this basic advice that seems to be the most helpful to me personally; I’m just getting started.
 
J300UM

Unlike some forums, we want everyone here to learn from one another. There is a lot of experience and talent here, as well as a lot of respect for one another.

Thanks for asking a very good question.

JD338
 
Wow! Thanks for all the info guys! I have always used 3 shot groups to develope my loads and it has always seemed to work well. I read a little bit about the ladder method and thought what the heck. I'm never opposed to trying something new, especially when I'm getting ready to start working up loads for a cartrige that nobody has data for.
 
JD338":3mn6eovk said:
J300UM

Unlike some forums, we want everyone here to learn from one another. There is a lot of experience and talent here, as well as a lot of respect for one another.

Thanks for asking a very good question.

JD338

That's so true. There is no forum with a better or more respectful group of people! Probably because there are so few people from Massachusetts on this forum :wink:
 
I just had my 7mm STW rebarreled before hunting season. 30" single point cut barrel, installed by a top accuracy smith.
My old faithful load:
160gr Nosler AB
98gr wc860
Fed 215
Rem brass,

Well it was good enough to kill an antelope at 435yds, but I want to see what it can really do.

With my .338 Win Mag, I've had a hard time breaking .75 MOA, so I figure it might be time to try some new strategies. I've been using H4350, and WC852. I recently ordered more surplus powder, and included 16 pounds of H4831sc. I also have some WC846 that is showing promise. I like the 4350 because I'm getting 3150 with a 200 Gr AccuBond, but I'm will probably end up sacraficing some of that velocity for the accuracy I want.
 
Antelope_Sniper":1mw931o4 said:
With my .338 Win Mag, I've had a hard time breaking .75 MOA, so I figure it might be time to try some new strategies. I've been using H4350, and WC852. I recently ordered more surplus powder, and included 16 pounds of H4831sc. I also have some WC846 that is showing promise. I like the 4350 because I'm getting 3150 with a 200 Gr AccuBond, but I'm will probably end up sacraficing some of that velocity for the accuracy I want.

I would take a look at RL 19 in your 338 Win Mag with the 200 gr AB. :wink:

JD338
 
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