Ladder Test Interpretation

[TikkaSporter]

This is a ladder test that I tried with a 260 Remington at 500 yards, Reloader 17 powder, and 140 gmr AMax bullets.

Gold star for anyone that can identify the best node... It's a tough one

Incase anyone is interested the rest of the information for this test is below:

Rifle:
260 Remington
Defiance Deviant Hunter action
Bartlein barrel, 22", 3B contour, 1:8.2 twist, no brake, 46 rounds at start of test
Manners T1 100% carbon fiber stock
Chambered and bedded by GAP

Conditions:
6200 ft elevation
29.9 Baro pressure
57 F avg temperature
19.5% humidity
Sunny, no clouds
Started at about 8:00 am... Ended around 9:00 am
Wind less than 5mph

Loads:
Reloader 17 powder
140 gr Hornady AMax
Lapua Brass
Federal 210M primers
36.0 - 41.0 gr in 0.5 gr increments
2.805" COAL = 0.020" jump to lands
- 1X fired brass, 0.002" neck tension

 

[Down South]

Yeah, its a tough one to figure out......lol

 

[chkunz]

It would be interesting to know how many folks do not actually get a node with the ladder test. Considering all the talk about nodes it may be considered failure if you do not clearly get a node so it goes unreported. But it may not be failure, it just may be data and the challenge is to interpret the data correctly (ignore the horizontal and only look at vertical and velocity). You may want to repeat the test with more data points. If you would like to try a different load some folks use H4350 and 142 Sierra Match Kings in the 260 at long range with good results. I have never actually done a ladder test but I did stay at a Holiday Inn once.

 

[fredhorace77]

id go with 40.5

 

[chkunz]

I know this is going to be considered heresy but with all the attention to ladder tests and tuning on nodes I have not yet seen anyone show with data why tuning on a node is preferable to tuning on some other point. I have seen some beautiful theory that supports this practice and it is impressive theory. It looks like a good thing to do and we can give a lot of opinions as to why it should be a good thing to do but since so many folks have so much invested in the procedure it would be good to back up the practice with data.

 

[Sniper338]

For what its worth I see a clear 38.0 to 39.0 range to play in. I havent heard of many people using reloader 17 in a 260 though.

I run a 260 Tac chambered 260... (slightly longer freebore for seating longer bullets) My theory is many people have a regular 260 chamber and try to run heavy longer 140gr or 142gr vlds but they cant seat them out right with a regular 260 chamber, to fit the chamber the bullets stuck in the case too deep like this... I know several people that have tried to make it work and they for the life of them can not get their rifles to shoot as well as mine does with 140gr bullets. After lots and lots of me trying to explain this they finally tried 130 gr bullets that are slightly shorter in length and they had more success.

I use:
deviant action
brux 28 inch barrel
ross schulers brake
manner stock jewell trigger..

I use 140 berger hunting vlds and 42.0gr H4350 and it shoots VERY WELL!!! H4350 has been across the board the best powder for this cartridge that I have personally seen. I assume you are looking for speed by using reloader 17... Well, your shorter barrel hindered that to start with. With my 28 inch barrel I am pushing these bullets right on the hind end of 6.5x284 velocities. It shoots in the 2950+- range.

So what I am saying IMO and IMO only you should try H4350 and try to find accuracy with it, not velocity... I just ended up with a fast barrel I think, I shot for accuracy to find my load way before I even chronoed it..


but to your original question I would shoot another test and compare them... and see if 38-39 shows up again.. another food for thought is with that powder your already at less case capacity, I usually like powders that fill a case better which the H4350 does with this... just throwing it out there you have 38-39gr of powder in a round, I have 42... my case is filled a bit more... take it all as you may.. jmo here.

 

[BountyHunter]

shoot it again but with a chrono this time and record the MV for each. see if large MV jumps match the target POI. nodes tend to have close POI and closer MV than non node points

 

[TC260]

I know this is going to be considered heresy but with all the attention to ladder tests and tuning on nodes I have not yet seen anyone show with data why tuning on a node is preferable to tuning on some other point

You don't need to search for "data", just try it a few times and prove it to yourself. If it works, great. If not, then go back to the old methods.

 

[TikkaSporter]

Thank you for the advice in your post. There's a lot to take in there.

I also tried H4350 and 140 gr Berger Hybrids using the 'long range load development at 100 yards' method that Erik Cortina posted up (which appears to be a derivative of the OCW method). You can see my results posted today in that thread, page 100 ... That will probably be the go-to combination for this stick, as it is for many. Somewhere around 41.5 gr?... I had this rifle built with a Wyatt long BDL box, and throated to run the 140 Hybrids...

I was hoping to find a little more velocity with the RE17 powder since I have about 16lbs of it laying around, maybe find a hunting load with for the AMax's.

For what its worth I see a clear 38.0 to 39.0 range to play in. I havent heard of many people using reloader 17 in a 260 though.

I run a 260 Tac chambered 260... (slightly longer freebore for seating longer bullets) My theory is many people have a regular 260 chamber and try to run heavy longer 140gr or 142gr vlds but they cant seat them out right with a regular 260 chamber, to fit the chamber the bullets stuck in the case too deep like this... I know several people that have tried to make it work and they for the life of them can not get their rifles to shoot as well as mine does with 140gr bullets. After lots and lots of me trying to explain this they finally tried 130 gr bullets that are slightly shorter in length and they had more success.

I use:
deviant action
brux 28 inch barrel
ross schulers brake
manner stock jewell trigger..

I use 140 berger hunting vlds and 42.0gr H4350 and it shoots VERY WELL!!! H4350 has been across the board the best powder for this cartridge that I have personally seen. I assume you are looking for speed by using reloader 17... Well, your shorter barrel hindered that to start with. With my 28 inch barrel I am pushing these bullets right on the hind end of 6.5x284 velocities. It shoots in the 2950+- range.

So what I am saying IMO and IMO only you should try H4350 and try to find accuracy with it, not velocity... I just ended up with a fast barrel I think, I shot for accuracy to find my load way before I even chronoed it..


but to your original question I would shoot another test and compare them... and see if 38-39 shows up again.. another food for thought is with that powder your already at less case capacity, I usually like powders that fill a case better which the H4350 does with this... just throwing it out there you have 38-39gr of powder in a round, I have 42... my case is filled a bit more... take it all as you may.. jmo here.

 

[TikkaSporter]

Zoom in on the Ladder Test pic I put up... The velocities are there.... No surprise, the two in the same hole had the same velocity despite being 0.5 gr apart in charge weight... Too bad I didn't find a node at a higher velocity... May be I should re-shoot the upper half of it and go up a bit more in charge.

shoot it again but with a chrono this time and record the MV for each. see if large MV jumps match the target POI. nodes tend to have close POI and closer MV than non node points

 

[waldo1979]

The accuracy node appears to be around 38.5, but you should probably more groups as described in OCW to rule out shooter mishaps.

 

[dcali]

I'm with T-REX. Ladder tests have to be one of the most abused concepts out there. The whole idea is that with some barrels and some cartridges you will get a vibration pattern that will help cancel out the velocity variations. So you get a stair-step shaped impact point as you increase charge from target to target. (Actually, a sine wave if you subtract out the velocity difference).

Nowhere is it guaranteed that those "steps" are going to be the all around best combination of load and rifle. Rifle dynamics are much more complex than that - you've just got to try some loads and see what happens. There are no shortcuts. Not OBT, not OCW, not ladders, nor any other "system" you can come up with will make up for rounds down range. Pick a powder, get organized, and shoot some groups.

 

[nosualc]

It looks like you have a node at 38-39.

But a single ladder is not enough data. A single flyer can completely skew results.

I'd run 2 more ladders, compare results, and see what it tells you.

-nosualc

 

[jcampbellsmith]

I've run some similar tests in the past, however I've stepped up 0.2 gr at a time. As above, I would rerun the test and use smaller steps.

Regards

JCS

 

[dalej]

I'm with T-REX. Ladder tests have to be one of the most abused concepts out there. The whole idea is that with some barrels and some cartridges you will get a vibration pattern that will help cancel out the velocity variations. So you get a stair-step shaped impact point as you increase charge from target to target. (Actually, a sine wave if you subtract out the velocity difference).

Nowhere is it guaranteed that those "steps" are going to be the all around best combination of load and rifle. Rifle dynamics are much more complex than that - you've just got to try some loads and see what happens. There are no shortcuts. Not OBT, not OCW, not ladders, nor any other "system" you can come up with will make up for rounds down range. Pick a powder, get organized, and shoot some groups.

Don't understand your concept. Using components and barrel life shooting 5-shot groups is a waste of time. The ladder test posted shows where accuracy will be with bullet/powder combo. The OP achieved, in ten shots what you suggest he do in 50 shots. He can test 4 more powder/bullet combos and have a only 50 rnds down the tube and huge amount of usable data for him to judge the best load. Then shoot 5-round groups to prove his data correct. This is the way I load test new barrels.

 

[jpretle]

I would run .3g increments, beginning at 36g. I generally load incrementally, to beyond where I know I will pressure up. When I begin to see those pressure signs, I quit. I also clock my rounds looking for jumps in velocity and compare w/ what shows on the target.
I have on several occasions had 3 nodes that would be workable. I generally take the higher velocities, unless I am to near the pressure signs.

 

[dcali]

I'm with T-REX. Ladder tests have to be one of the most abused concepts out there. The whole idea is that with some barrels and some cartridges you will get a vibration pattern that will help cancel out the velocity variations. So you get a stair-step shaped impact point as you increase charge from target to target. (Actually, a sine wave if you subtract out the velocity difference).

Nowhere is it guaranteed that those "steps" are going to be the all around best combination of load and rifle. Rifle dynamics are much more complex than that - you've just got to try some loads and see what happens. There are no shortcuts. Not OBT, not OCW, not ladders, nor any other "system" you can come up with will make up for rounds down range. Pick a powder, get organized, and shoot some groups.

Don't understand your concept. Using components and barrel life shooting 5-shot groups is a waste of time. The ladder test posted shows where accuracy will be with bullet/powder combo. The OP achieved, in ten shots what you suggest he do in 50 shots. He can test 4 more powder/bullet combos and have a only 50 rnds down the tube and huge amount of usable data for him to judge the best load. Then shoot 5-round groups to prove his data correct. This is the way I load test new barrels.

I couldn't disagree more. With one shot per load, you have no idea if you are measuring the bullet's inherent dispersion, the rifle's vibration pattern, or a variation in velocity. And even if you luck out and hit the center of each group, you still aren't guaranteed that a "node" is the most accurate load. I've found that my rifles often won't show any meaningful correlation between accuracy and the change in vertical. I won't say a ladder test is bunk, but there is a lot more to it, and if it's all you're doing, you're probably not shooting the best load you can be.

 

[nosualc]

I don't think anyone recommends ladder testing as the end-all be-all way to determine optimum loads.

Properly done, it IS however, a very efficient way to eliminate lots of bad loads.

To use an analogy: It is said that 95% of all fish reside in 5% of any given body of water. There's no use fishing in the other 95%.

-nosualc

 

[jpretle]

I certainly didn't intend to imply the ladder test was the 'end all', in load development. Testing groups using charges in the nodes comes next. Verification of velocities of the node group charges should be considered and put/used in context. And one group shouldn't be used as the 'tell all', either.

 

[CharlieNC]

I'm sure it's just another coincidence, but your node in the 38.0-38.5 region just happens to fall perfectly on a OBT node when I plug your data in Quick Load.