Lets talk Ladder testing

[Darkside-Six]

greetings all,

Here's the deal. I have a lot of experience with long range shooting, however I am fairly new to reloading. I've only been reloading for less than a year and up until now it has only been for .223 and pistol rounds. Now that I want to begin precision rifle loading I need to find my optimal load. I understand the concept of ladder testing but I have not done one with respect to reloading yet. I've read many different ways to do them and from what I gather it is best to start with your lowest charge and move up.

From there, there seems to be many variations of how to do it. From firing 1 shot at every load and working up and then picking a few groups and load more, or by loading 3-5 of every load and firing each group separately.

I guess I'd like to hear what you all have done so I may figure out the best way to accomplish this.

Thanks!

 

[Joop]

I'm new to ladder testing, as well. I just did it for the first time with my newest rifle build. After all the reading I did on it, I decided that I wanted to use this method to determine two things. First, the max load for a given powder/bullet combo in my rifle. Second, along the way in finding the max load, I hoped to find accuracy nodes to give me the best idea of where to focus. I have to say that it worked fairly well in both departments. I started fairly low and worked up in half grain increments, with one shot per increment. The range I shot them at was 472 yards. I used a 4'x4' target board and just made squares on them with a marker that were approximately 3". I took my best guess at what the medium velocity would be for a given load and dialed the dope in for that velocity. This worked quite well, as they started low and worked their way up through and over the squares. In the end, it turned out that I could pretty much pick my velocity with each powder, as they were grouping in 1-1.5 grain increments, fairly consistently. For example, I would have 43.0 and 43.5 grains of powder that would would put the bullets right next to each other. Then, about 2-3" higher, the 44.0 and 44.5 grain loads would be tucked nicely together, and so on, all the way up the charge range. There were exceptions, of course and these would be outside the node, the way I was reading it. With those ranges, I knew I either needed to avoid them, or go higher if it was at the top (assuming there were no pressure issues). My goal was to get the best velocity out of a given powder and bullet, without sacrificing safety or accuracy. If I had tried to do this with five different powders and three different bullets, which is exactly what I had to work with, but shooting 3-5 rounds per increment, I would have probably had to sell a kidney or something to pay for all the reloading supplies! Another plus, is that I documented all of these tests in pretty good detail (for me, anyway) and, should I run out of X powder, or Y bullet, I can go back to this data and have some other options to fall back on. They may not be the "ultimate" load, but there were several that would still get the job done and I wouldn't have to start from scratch with any of them.

I have to admit. I've been a little skeptical of all the ladder and OCW talk over the last year or two. But, after having tried it, I can honestly say that it worked and gave me a lot more meaningful data than just shooting groups at 100 yards would have done. You could say I'm a convert, now.


John

 

[Darkside-Six]

Thanks for the reply Joop.

I may have to try something like this. I was debaiting shooting 1 shot per load and working from top to bottom, or starting somewhere in the middle with 3 bullets of each load and work up .5 grains at a time. like starting at 42, 42.5, 43, 43.5, 44, 44.5 and shooting separate groups of 3. From the sounds of it, your way probably would work better.

 

[hondo1312]

Helpful tip for ladder testing: buy a red, green, and blue sharpie to color your bullets with. You can shoot an unmarked bullet to leave a black hole, them the colored bullets to leave a red, green, and blue hole. This allows you to shoot 4 at a time before heading down range to mark your impacts with charge weight notations instead of heading down range after each shot. I shoot my first ladder test at about 300 yds then my second one at 600 yds.

 

[Joop]

Helpful tip for ladder testing: buy a red, green, and blue sharpie to color your bullets with. You can shoot an unmarked bullet to leave a black hole, them the colored bullets to leave a red, green, and blue hole. This allows you to shoot 4 at a time before heading down range to mark your impacts with charge weight notations instead of heading down range after each shot. I shoot my first ladder test at about 300 yds then my second one at 600 yds.

Great advice and it works well.

I should also add that, after my initial test, I actually did load for three round groups for a few specific nodes and tested them in the second stage. However, most of these were one load of each powder type and things kind of branched out from there. So, I think you just have to go where the results are leading you and what worked for me may not be exactly the same for you. But, I still feel as though I saved a lot of time and components by only doing one shot per increment to start with. YMMV.

John

 

[2clicks]

Love the ladder test. I shoot in half grain increments low to high for instance 22, 22.5, 23, 23.5, 24 grains all in a row. Group testing I believe defeats the ladder concept. I then fine tune when I find the horizontal flat spot. Example: 75Amax with 23, 23.5. of IMR4895 groups together side by side but 22.5 and 24 grains were 2 inches lower and higher than the 2 shots that were closest together. (I also shoot the test at 600) the velocity spread really separates the holes at that range. In this case I would run with 23.3 and call it good. That's actually my High power 600 yard line load with my AR Lake city brass and winchester primers 8 thousandths off the lands of my Krieger barrel it's wicked accurate. Also don't worry about the left or right so much. Thats not the point of the ladder, it's when the up and down stops and the barrel is't moving for a couple shots that your looking for. In my mind you can have a low and high charge accuracy node but so much in between, charge weights grouping close together. I get about a 2-3 shot flat spot and I go with the middle charge weight. Every time I run one the holes climb up the target, a couple shots will be together (side by side) then they continue to climb up away from the cluster. Best of luck to Ya!

 

[Darkside-Six]

Love the ladder test. I shoot in half grain increments low to high for instance 22, 22.5, 23, 23.5, 24 grains all in a row. Group testing I believe defeats the ladder concept. I then fine tune when I find the horizontal flat spot. Example: 75Amax with 23, 23.5. of IMR4895 groups together side by side but 22.5 and 24 grains were 2 inches lower and higher than the 2 shots that were closest together. (I also shoot the test at 600) the velocity spread really separates the holes at that range. In this case I would run with 23.3 and call it good. That's actually my High power 600 yard line load with my AR Lake city brass and winchester primers 8 thousandths off the lands of my Krieger barrel it's wicked accurate. Also don't worry about the left or right so much. Thats not the point of the ladder, it's when the up and down stops and the barrel is't moving for a couple shots that your looking for. In my mind you can have a low and high charge accuracy node but so much in between, charge weights grouping close together. I get about a 2-3 shot flat spot and I go with the middle charge weight. Every time I run one the holes climb up the target, a couple shots will be together (side by side) then they continue to climb up away from the cluster. Best of luck to Ya!

Very nice.

so if I understand this correctly, I should run the ladder with 1 round per load, and then maybe take 2 or 3 of the ones that grouped the most and make a 3 round group with them to narrow it down?

 

[2clicks]

Yes if you initially run half grain increments. Example say 22.5, 23, and 23.5 were all on line you could run another test with .3 grain increments say 22.8, 23.1, 23.4 I also use a chrony while testing I like to note the velocities next to the charge increases in my note book every once in a while a higher powder charge might be slower in speed and it's important for me to know this since it won't print on target properly. That's one step a lot of guys wont take but think about it 50 fps is about 2 inch up or down on the target at 600 yards. This way you can verify increase in bullet speed and increase in powder charge they should coincide with each other. if not and sometimes they don't you will have a faulty test. I really dug hard on this issue with my 260 loading I racked my brain over it. (in a nut shell my 43.1 charge was sometimes faster than my 43.4 charge I wouldn't have known that if I wasn't using the chrony) As it turns out my chargemaster throws needed to be double checked they were off by few tenths of a grain after double checking the weight I got it all squared away now.

 

[Darkside-Six]

Sounds good, I think that is the rout I'll try then.

Much appreciate!

 

[Rat807]

Yes if you initially run half grain increments. Example say 22.5, 23, and 23.5 were all on line you could run another test with .3 grain increments say 22.8, 23.1, 23.4 I also use a chrony while testing I like to note the velocities next to the charge increases in my note book every once in a while a higher powder charge might be slower in speed and it's important for me to know this since it won't print on target properly. That's one step a lot of guys wont take but think about it 50 fps is about 2 inch up or down on the target at 600 yards. This way you can verify increase in bullet speed and increase in powder charge they should coincide with each other. if not and sometimes they don't you will have a faulty test. I really dug hard on this issue with my 260 loading I racked my brain over it. (in a nut shell my 43.1 charge was sometimes faster than my 43.4 charge I wouldn't have known that if I wasn't using the chrony) As it turns out my chargemaster throws needed to be double checked they were off by few tenths of a grain after double checking the weight I got it all squared away now.

I'd like to add a couple things you may want to do. Finding to max charge for any bullet, powder, primer will also include the seating depth of the bullet. After you have found a sweet spot where several consecutive shots form a small group, (as 2clicks described) I load 5 rounds from .2 grains below the start and increase by .3 grains or so and go just over the highest sweet spot's charge weight. So using 2clicks weights of 22.5 - 23.5, Id load 5 at 22.3, and evenly space up to 23.7. We have large target boards and can place multiple targets downrange. I setup 4 or 5 targets and first shoot at least 3 fouler shots then start the 5 shot groups. 1 shot on target #1, then move to the next charge wt and shoot target #2, next charge wt and shoot target #3, etc. After these rounds are all fired, the best two groups I also seat the bullets at different depths and shoot more groups. Only once has a max load been the best group so seating the bullet deeper, I had to calculate (from previous data collected) velocity changes per 10 thousands depth change, and go from there. Changing the powder charge in this sweet spot by a 10th or two should not matter very much, but when you jam the bullet into the lands and play with the seating depth, better safe than sorry.
Ex My .280 ogive measurement to the lands is 2.709 I have loads that measure at 2.705 and 2.700 and one 140 Berger load that likes 2.665. 150 gr Nosler Bal tips like to be jammed.

 

[FunkBass2008]

I live in CA and there really isn't much space to do a true ladder test. So I just recently loaded 4 loads at .3 grain intervals and three of them grouped at 1" while one load shot right around .5". Seems to do the job for me okay... When I find enough range I'd like to try a true ladder test with the same loads. I assume I would find that sweet load to still come up on top.

 

[longun83]

Helpful tip for ladder testing: buy a red, green, and blue sharpie to color your bullets with. You can shoot an unmarked bullet to leave a black hole, them the colored bullets to leave a red, green, and blue hole. This allows you to shoot 4 at a time before heading down range to mark your impacts with charge weight notations instead of heading down range after each shot. I shoot my first ladder test at about 300 yds then my second one at 600 yds.

I shot a ladder at 200 by myself, using my spotter scope...... After about 6 or 7 shots landing closely to each other I had a few holes which were marked with ? because I wasn't smart and I didn't have a spotter.

 

[Jhnmdahl]

Make a separate target (spot on the paper) for each charge weight, and don't shoot from so far away that your rounds end up impacting near other targets. You may still want to let the barrel cool between shots, but it should save you some time. Some say to shoot groups of 3 for each charge weight, and to shoot one of each charge weight (progressing from lowest to highest) before shooting the second of each charge weight, etc. Then, don't only look at group size, but look for little variation from one charge weight to the next in picking a charge weight that isn't sensitive to charge weight variations.

 

[steve123]

I recently did a ladder for my new 6x47L barrel. Although I've done many ladders I decided to try something different this time. I did .1 grain increments at 400 yards. The high node was obvious with 5 shots into .9". The low node wasn't much bigger for four of the shots. In short, those 30 rounds yielded zero doubt as to where the middle of a node was, unlike some other ladders in the past.

Worth mentioning... let your barrel cool and pick a calm morning!

 

[longun83]

I shot a ladder at 200 by myself, using my spotter scope...... After about 6 or 7 shots landing closely to each other I had a few holes which were marked with ? because I wasn't smart and I didn't have a spotter.

I'm thinking I need to concentrate on 42gr and up. This was with IMR4895, 168gr AMAX, CCI 200, and Norma brass.
Rem700AACSD @ 200 yards.