My First Ladder Test

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Adamg_55

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Ok, so ive got my MDT Tac 21 all put together, the only thing its missing is a super sweet load. So that is what im trying to find now, so i can post a grouping worthy of the Tac 21 Chassis. I read Mystics article on ladder testing and this was my attempt.

Let me say first that this is my first bolt action rifle and my first attempt at finding true accuracy. The test results do show some positive info, but some of it is truly clouded by my inability to shoot well.

So i loaded up two sets of rounds, both using Varget and standard winchester primers. I used Hornady 168gr match bullets in 1 load and 175gr SMKs in the other. All the brass was fireformed for this rifle. The rifle is a rem 700 5R Milspec sitting in an MDT Tac 21 chassis. I was shooting off a bipod, atlas accushot, and using a rear bag.

It seems that the 168gr grouped much better, i shot them first, and looking at the second loads using the 175gr SMK, im really not sure why my shooting went to sh*t. But it is what it is.

Also all of this shooting was done at 200yrds.

So first target using the 168gr.
starting load was with 42gr of varget and an COL of 2.800
max load was 45gr of varget.
went in .3gr incriments
DSC00068.jpg


The best groupings were at 42.6grs measure .773", and 44.7gr measures .753" So at 44.7 am i too close to max? ive heard there are pressure signs, but not sure what to look for. I saved the brass and know which ones were from which amount of powder, so if i know what to look for i can probly figure it out.

The second target was using varget starting at 42gr and working my way up to 45gr, using 175gr SMK with a COL of 2.800. Not sure what i did wrong when shooting at this target, but i just didnt feel like i was doing as well as the above. The sweet spot seems to be at 42.9gr measuring 1.064". The last little target with the 45 gr of varget i only hit with one shot? lol not sure where the other one went.

DSC00067.jpg



So this was my first ladder test and i am pleased with how it went, except for the second target. But it was fun and i am enjoying trying to find a recipe my rifle likes. Any tips for a beginner?


also a pic of the rifle shooting these groups
DSC00066-1.jpg
 
Ladder Test

Hey Adam
When you are doing your ladder test , don't get caught up in the group size, it's more about the group shape!
Group's that string vertically will not be a good long range round, if all your rounds are at the same level horizontal will in the long run be more accurate or more consistent at long range!!

I got most of my information from Jerry at Mystic Precision, he has some really good articles on reloading and ladder test!

on your 168 traget 42.5 grs,and 44.7 look good, and on the 175, 42.3,42.6,43.5 also look good!

Just my 2 cents
 
ipscshooter said:
Hey Adam
When you are doing your ladder test , don't get caught up in the group size, it's more about the group shape!
Group's that string vertically will not be a good long range round, if all your rounds are at the same level horizontal will in the long run be more accurate or more consistent at long range!!

I got most of my information from Jerry at Mystic Precision, he has some really good articles on reloading and ladder test!

on your 168 traget 42.5 grs,and 44.7 look good, and on the 175, 42.3,42.6,43.5 also look good!

Just my 2 cents
Click to expand...

Now that you mention it i do remember reading about the horizontal stringing being the best. The wind was blowing crazy hard today!

Thanks for the tip
 
What you are looking for in a "ladder test" is a pattern where you are increasing powder charge and velocity, but you are not seeing a rise in the point of impact, or perhaps even a slight dip. You ignore any horizontal difference between bullets (as it most likely due to wind and random inaccuracy). Distance exaggerates the effect. 200 meters is better than 100, but 300 meters is better still.

The idea is that you are trying to find a velocity where the barrel is vibrating upward and is near the peak of vibration up when the bullet exits. Faster bullets will exit lower in the vibration cycle with the barrel not pointing up so much. Slow bullets will exit with the barrel pointing higher. The differences in position compensate for the velocity variation.

What I find works best is to use separate targets (like you have done), but shoot 3 shots per target. Measure the height only of each bullet in the target above a common point (ignore any horizontal), and average that for the three bullets on each target. Then last plot the height of these averages on a graph vs powder charge. On this graph you are looking for flat spots where increased powder does not give a rise in elevation. See the example below. The graph shows three different bullets shot at 300 meters.

LadderGrains.jpg
 
DrawBlood said:
It isn't technically one, but it got results, and that's the important thing, right?
Click to expand...

I am not crazy about 2 shot load development, here is why; it is clear the shooter is making an honest attempt at learning what his rifle likes to be fed, he has invested significant time and expense in this effort, but unfortunately the target yields no useful information. People advocating 2 shot load development should expect these kind of results. There is no way of knowing what the 2 shots represent in this methodology. Put it another way, many a barrel has been wasted trying to duplicate a lucky group early on in load development.

For example, is the first shot a flier, is the second, are they both? Did the wind move the first bullet or second bullet, or both? Did the rifle move different on the bags or bipods under recoil? Is the barrel warping? This list of anomalies is infinite if we don't at least start to see a pattern to narrow things down.

I can't honestly look at these targets and make any suggestions other than to say the wind appears to be a big factor and there may be some gun handling issues judging by the vertical. The shooter needs to at least try 3 shot groups at a bare minimum to try and find a pattern. 5 shot is better but not always practical depending on cost, time etc. Once you find a load where the bullets start to touch or almost touch at 100 yds then you have something to work with and build around.

Just my honest opinion in hopes that the shooter not waste another bunch of his valuable components and time.

Lastly, if you want to cut your group size by a min 40% at least get one flag to shoot over, planted at 25 yds, indicating wind direction and intensity, and only pull the trigger when the flag is indicating the same direction and intensity. A piece of survey tape 3' long on a stick or rebar will get you going.
 
so im no expert on ladder testing, iv always figured my stuff out by shooting groups at distance... so maybe some one can fill me in..

it looks like the OP was doing 2 shot "groups" is this enough to get any kind of information out of?

im honestly not trying to put any one down but it seems like 2 shots per load and a self admited "inability to shoot well" wont tell you any thing, wouldnt minimum 5 shot groups be better? if not 2 groups of 5 of the same load?
 
Wow, some of you guys are harsh! Haha I definatly can't shoot all that well, and I was following mystic precisions article on his version of a ladder test. It's not a ladder test by definition but a hybrid. Either way I'll be back out next week to try some more loads. Gotta start somewhere!
 
Great start but focus on the 168's for now as they gave you positive results.

Now go back to 44.5 and work up in 0.1gr increments to 44.8gr. you can increase to 3rds now and try and repeat a few times after letting the barrel cool.

Say 3- 3rds groups or 5 -2rds groups taking a break to let the barrel cool and shoot each group on a different target. Be aware of how you feel - fatigue or sore shoulder.

Pay attention to the winds and if the load is good, you will repeat the 3/4" or smaller accuracy with little to no vertical like the bottom center group. The location of the group on the target will be the same. Use the targets that are on the same level.

You want three consecutive groups that mimic each other. Be careful that shooting off a bipod can create some error but if you are consistent with your follow through, each group should look similar - flat and small in the same relative position.

Voila, you have found your load. Now if it makes you feel better or to meet the needs of others, shoot in larger strings. This will be a good test to see how the barrel reacts to heat.

So let's say you want to go to 5 or larger strings. If all is well with your load and your shooting, the first 3 will drop into a flat 3/4" type group (you have already proven that above), now keep track of where each following shot lands.

The group should not get appreciably bigger, in fact the bullet should just make bigger hole BUT if you start to see the shots move out of the group, note the number and location. Take another shot or two and see if the condition get worse. Likely it will.

Let the barrel cool to ambient. Start again and track how the shots land.
Unfortunately, factory barrels have a tendency to warp as they heat up and the warping is usually repeatable.

If the stringing repeats, you know that the barrel can only be so hot before it needs a rest.

This is why testing on the calmest day with flags is important. You are tracking the POI of the rifle not how well you shoot or how much the air is affecting your results.

When you understand how the barrel reacts to heat and you know that the barrel will shoot X MOA, go ahead and try another powder or bullet combo. You have a baseline on what the rig can do. You will have the point of reference to find other workable combos.

Good shooting.

Jerry
 
Adam don't be to hard on yourself. I have tried many methods of finding the pet load for a gun. The one I keep coming back to is the true ladder test of 20 rounds loaded .2 - .3 grains apart in powder and let off a couple of fowling shots and go on one sheet of paper from start to finish all 20 rounds, aiming at the same point. Then I go with a few 3 shot groups where clusters formed. It takes a while but trigger time is a good time!!
Have fun.
 
ultimate_monkey said:
so im no expert on ladder testing, iv always figured my stuff out by shooting groups at distance... so maybe some one can fill me in..

it looks like the OP was doing 2 shot "groups" is this enough to get any kind of information out of?

im honestly not trying to put any one down but it seems like 2 shots per load and a self admited "inability to shoot well" wont tell you any thing, wouldnt minimum 5 shot groups be better? if not 2 groups of 5 of the same load?
Click to expand...

The original ladder test only used one shot per load. It can work with custom guns that can shoot less than 1/4 MOA, but typically generates garbage with hunting accuracy guns.
 
tigrr said:
Adam don't be to hard on yourself. I have tried many methods of finding the pet load for a gun. The one I keep coming back to is the true ladder test of 20 rounds loaded .2 - .3 grains apart in powder and let off a couple of fowling shots and go on one sheet of paper from start to finish all 20 rounds, aiming at the same point. Then I go with a few 3 shot groups where clusters formed. It takes a while but trigger time is a good time!!
Have fun.
Click to expand...

Best way to do it.

I also go .5 to quickly find my high node. Than .1 in 3 shot groups. And The best is my load. I'll continue to test around the .1's but it's usually done pretty quick.

Also testing is done at a range of 500-600 yards
 
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