3 shot group vs ladder tests

[JFrank]

Hey so what is your load development and to possibly make it more detailed say for a rifle and a cartridge your not familiar with? Just say an average feller

I like your no nonsense approach to alot of your post and sorry if there is a consensus for load development on this forum .excuse my ignorance if so.thanks in advance

I’m not ignoring you, I just think there are other LRBR guys that know a hell of a lot more than I do. Three of them already posted on this thread.


Jim

 

[Dave Way]

I recommend running your “ladders” with three shot groups. Single shot ladders can be especially misleading. Two shot ladders may tell you what a barrel doesn’t like, but they won’t necessarily tell you what a barrel likes. You get more information about grouping, flat spots as well as how each of the charges “moves” shooting three shot “ladders”.

Remember, you aren’t looking for different charges that produce the same velocity. You are looking for points where the barrel harmonics and the velocity dump different charges into the same group(elevation).

Here is an old 1K three shot AA2495 ladder I shot when H4895 was in short supply. Two nodes were identified for this BRA barrel. Next step was a three shot test with a finer 1/10th grain increment. Sorry about the joke Roy!



Things get tougher at 600 yards because shots start to cluster closer together, hopefully. Here is an old 600 yard ladder again with a BRA. Shortly after shooting this, the barrel, with 29.7 gr., shot the smallest 8 target aggregate ever shot at IBS Nationals. It was 1.611”

Notice the overlap of 29.7, 29.8 and 29.9. I like it when a lighter load prints on top of or preferably slightly higher than a heavier load. I will pick it every time. Sorry shot marker guys, but you really need a piece of paper in your hand to let it talk to you. It’s all about those triangles!



Here is a seating “ladder”. I had a proven load with this 6.5x47L but was concerned about throat movement firing a 16 target match. The left to right wind kept picking up as I shot but you can see that .006” jump all the way up to .018” shot at about the same elevation so I had .012” of erosion to play with.



This barrel and load ended up shooting a tiny 1.338” group at the Rendezvous three weeks later. The bottom line is three shot group “ladders” help me develop sound loads while minimizing round count. I then verify with 5 or ten shot groups depending on the match I’m tuning for.



Dave.

 

[Alex Wheeler]

And thats how its done. Multicolored triangles have led to a lot of success! Its not that complicated guys! And I agree, theres something to seeing the paper. I just dont see the same thing on the e targets for some reason.

 

[Webster]

If you can illustrate how drawing an angled line on top of a plot someone is using to find flat spots is different than the way they drew the flat lines, maybe the cynicism might be interesting.

142 replies to explain what a good group looks like.

 

[quest450]

Great post by Dave there’s not much to add but maybe my failed attempt at a coarse ladder testing my new 300wsm barrel

 

[Owens85]

I recommend running your “ladders” with three shot groups. Single shot ladders can be especially misleading. Two shot ladders may tell you what a barrel doesn’t like, but they won’t necessarily tell you what a barrel likes. You get more information about grouping, flat spots as well as how each of the charges “moves” shooting three shot “ladders”.

Remember, you aren’t looking for different charges that produce the same velocity. You are looking for points where the barrel harmonics and the velocity dump different charges into the same group(elevation).

Here is an old 1K three shot AA2495 ladder I shot when H4895 was in short supply. Two nodes were identified for this BRA barrel. Next step was a three shot test with a finer 1/10th grain increment. Sorry about the joke Roy!

View attachment 1674550

Things get tougher at 600 yards because shots start to cluster closer together, hopefully. Here is an old 600 yard ladder again with a BRA. Shortly after shooting this, the barrel, with 29.7 gr., shot the smallest 8 target aggregate ever shot at IBS Nationals. It was 1.611”

Notice the overlap of 29.7, 29.8 and 29.9. I like it when a lighter load prints on top of or preferably slightly higher than a heavier load. I will pick it every time. Sorry shot marker guys, but you really need a piece of paper in your hand to let it talk to you. It’s all about those triangles!

View attachment 1674551

Here is a seating “ladder”. I had a proven load with this 6.5x47L but was concerned about throat movement firing a 16 target match. The left to right wind kept picking up as I shot but you can see that .006” jump all the way up to .018” shot at about the same elevation so I had .012” of erosion to play with.

View attachment 1674553

This barrel and load ended up shooting a tiny 1.338” group at the Rendezvous three weeks later. The bottom line is three shot group “ladders” help me develop sound loads while minimizing round count. I then verify with 5 or ten shot groups depending on the match I’m tuning for.

View attachment 1674579

Dave.

That's the way many LRBR shooters do it and its simple and works!!!! Sometimes I think people can make things wayyy more difficult then it really is. This method works and that's all that matters!!

 

[Dave Way]

Great post by Dave there’s not much to add but maybe my failed attempt at a coarse ladder testing my new 300wsm barrel

View attachment 1674591

Mark, did you experience heavy bolt lift at the top end? It may want more powder or you may have a bag issue. Just guessing.

Dave.

 

[quest450]

Mark, did you experience heavy bolt lift at the top end? It may want more powder or you may have a bag issue. Just guessing.

Dave.

That’s an excellent guess Dave, no heavy bolt lift, I ran that ladder test late Friday evening before the match and just ran out of time so ended up adding more powder 61.0 grains of H4350 @ about 2900 fps and shot this group the next morning, sometimes you get lucky, I need to tweak this load a bit next time I get a chance to shoot 1K again

 

[Dave Way]

That’s an excellent guess Dave, no heavy bolt lift, I ran that ladder test late Friday evening before the match and just ran out of time so ended up adding more powder 61.0 grains of H4350 @ about 2900 fps and shot this group the next morning, sometimes you get lucky, I need to tweak this load a bit next time I get a chance to shoot 1K again


View attachment 1674662

Bingo.

 

[quest450]

I never preload at home before I travel, another quick ladder test at 1K before the Rendezvous, this was a fairly new barrel 160 rounds on it an I’ve never shot 1K with it only one 600 yd match, ended up with the same load

 

[Varminterror]

Target Ladders are an entirely different species than Velocity Curves.

 

[quest450]

leave your chrono at home....paper NEVER lies !!

 

[Bc'z]

leave your chrono at home....paper NEVER lies !!

That's gospel right there.

 

[Rope2horns]

Ladder tests are stooopid....please don't do them.

 

[Alex Wheeler]

Ladder tests are stooopid....please don't do them.

Let me guess, We should also tune at 100 yards and not chase the lands? LOL

 

[LVLAaron]

I just dont see the same thing on the e targets for some reason.

Oh boy... here we go

 

[JFrank]

Good stuff @Dave Way and thanks for sharing your work.

 

[Steve Donlon]

I recommend running your “ladders” with three shot groups. Single shot ladders can be especially misleading. Two shot ladders may tell you what a barrel doesn’t like, but they won’t necessarily tell you what a barrel likes. You get more information about grouping, flat spots as well as how each of the charges “moves” shooting three shot “ladders”.

Remember, you aren’t looking for different charges that produce the same velocity. You are looking for points where the barrel harmonics and the velocity dump different charges into the same group(elevation).

Here is an old 1K three shot AA2495 ladder I shot when H4895 was in short supply. Two nodes were identified for this BRA barrel. Next step was a three shot test with a finer 1/10th grain increment. Sorry about the joke Roy!

View attachment 1674550

Things get tougher at 600 yards because shots start to cluster closer together, hopefully. Here is an old 600 yard ladder again with a BRA. Shortly after shooting this, the barrel, with 29.7 gr., shot the smallest 8 target aggregate ever shot at IBS Nationals. It was 1.611”

Notice the overlap of 29.7, 29.8 and 29.9. I like it when a lighter load prints on top of or preferably slightly higher than a heavier load. I will pick it every time. Sorry shot marker guys, but you really need a piece of paper in your hand to let it talk to you. It’s all about those triangles!

View attachment 1674551

Here is a seating “ladder”. I had a proven load with this 6.5x47L but was concerned about throat movement firing a 16 target match. The left to right wind kept picking up as I shot but you can see that .006” jump all the way up to .018” shot at about the same elevation so I had .012” of erosion to play with.

View attachment 1674553

This barrel and load ended up shooting a tiny 1.338” group at the Rendezvous three weeks later. The bottom line is three shot group “ladders” help me develop sound loads while minimizing round count. I then verify with 5 or ten shot groups depending on the match I’m tuning for.

View attachment 1674579

Dave.

{Remember, you aren’t looking for different charges that produce the same velocity. You are looking for points where the barrel harmonics and the velocity dump different charges into the same group(elevation). ................. Thanks for pointing out it's value, I've been doing it but never thought about it. But I don't use a chronograph. I just use the JBM chart. And I thought it was a node when different charges went into the same group. Then we fine tune. There is plenty of information on where nodes are in different calibers if, like others have said, you have a good barrel and it is in tune . And your reloading skills are good. That is why I have not needed to do a ladder test. I am not in the same league as you, but just pointing out that you don't really need a ladder test to become a very good shot.

 

[precision1]

I recommend running your “ladders” with three shot groups. Single shot ladders can be especially misleading. Two shot ladders may tell you what a barrel doesn’t like, but they won’t necessarily tell you what a barrel likes. You get more information about grouping, flat spots as well as how each of the charges “moves” shooting three shot “ladders”.

Remember, you aren’t looking for different charges that produce the same velocity. You are looking for points where the barrel harmonics and the velocity dump different charges into the same group(elevation).

Here is an old 1K three shot AA2495 ladder I shot when H4895 was in short supply. Two nodes were identified for this BRA barrel. Next step was a three shot test with a finer 1/10th grain increment. Sorry about the joke Roy!

View attachment 1674550

Things get tougher at 600 yards because shots start to cluster closer together, hopefully. Here is an old 600 yard ladder again with a BRA. Shortly after shooting this, the barrel, with 29.7 gr., shot the smallest 8 target aggregate ever shot at IBS Nationals. It was 1.611”

Notice the overlap of 29.7, 29.8 and 29.9. I like it when a lighter load prints on top of or preferably slightly higher than a heavier load. I will pick it every time. Sorry shot marker guys, but you really need a piece of paper in your hand to let it talk to you. It’s all about those triangles!

View attachment 1674551

Here is a seating “ladder”. I had a proven load with this 6.5x47L but was concerned about throat movement firing a 16 target match. The left to right wind kept picking up as I shot but you can see that .006” jump all the way up to .018” shot at about the same elevation so I had .012” of erosion to play with.

View attachment 1674553

This barrel and load ended up shooting a tiny 1.338” group at the Rendezvous three weeks later. The bottom line is three shot group “ladders” help me develop sound loads while minimizing round count. I then verify with 5 or ten shot groups depending on the match I’m tuning for.

View attachment 1674579

Dave.

Thanks for the detailed explanation and taking your time much appreciated!
It's easy to get into the weeds and question yourself

 

[KMW 1954]

Well I have thoroughly enjoyed this conversation.

Undetermined if I have learned anything or altered any views. Will probably just keep doing what I have been doing and be happy with it. It seems to work. How and why I cant answer. Is it right or wrong? Again, it works for me.