Ladder test/grouping test all in one?

[IA_shooter]

Just curious if anyone is doing a ladder test/grouping test of several different charges at the same time? For example, what I mean by that is loading up 3 rounds of each charge like I'm doing for the 1st time to try this. I'm loading up 3 each of charges of 43.6, 43.8, 44.0, 44.2, 44.4, 44.6, and 44.8 of Varget to test some 175 grain Sierra TMKs in my 308.

I plan on shooting at fairly good sized cardboard backer @ 300 yards with seven different small targets all in a horizontal line so I can compare the fall/rise of the POI for each charge and see if any of these charges also group really well at the same time.

Good way to test or ? Should I load 5 of each? Thoughts?

Thanks.

 

[dmoran]

That will work fine (IMO), and is a group test, since 7 separate aim points will be used for the 7 increments.
Where a ladder test is using 1 aim point for all increments.

Good luck.... and let us know your results !.!.!
Donovan

 

[IA_shooter]

That will work fine (IMO), and is a group test, since 7 separate aim points will be used for the 7 increments.
Where a ladder test is using 1 aim point for all increments.

Good luck.... and let us know your results !.!.!
Donovan

I just thought it would work as a ladder test as well since the aim point on each is on the same exact horizontal line and I can compare the vertical difference between them all.

 

[dmoran]

I just thought it would work as a ladder test as well since the aim point on each is on the same exact horizontal line and I can compare the vertical difference between them all.

With any target configuration, horizontally or not, by measuring & assessing the groups POI's from the POA vertically, would be a form off ladder analysis. With that said, any group test could be considered a form of a ladder test, when assessed by vertical dispersion.
Donovan

 

[jlow]

That will work fine (IMO), and is a group test, since 7 separate aim points will be used for the 7 increments.
Where a ladder test is using 1 aim point for all increments.

Good luck.... and let us know your results !.!.!
Donovan

I think you have mentioned the disadvantage of different aim points i.e. in our discussion of ladder vs. OCW - I think it would be useful to comment in general on the pros and cons of using different aim points i.e. why.

In addition, it would also be useful to know disadvantage of say running 2-3 ladders on separate targets boards with one ladder per board – so still 2-3 different aim points, vs. how the OP is describing it i.e. 7 aim points.

 

[DHuffman]

Definitely will work! I shoot 3 shot groups as you say individual targets on a horizontal plane so POI can be compared to POA easily on a three shot group versus a single shot on a ladder.

Start your charge weights @ 43 as there is usually a very good node @ 43.5

 

[jlow]

The thing is with 3 shots on targets line up horizontally as per the OP idea, what is then the difference between this and an OCW? This is of course being shot at longer distance i.e. 300 vs. 100 yards but with this, you are disregarding the laterals because of potential effect of wind so it seems like then you are getting closer to real life conditions i.e. longer distance but at the same time loosing some data?

Not being critical but just trying to get a discussion going.

 

[dmoran]

The thing is with 3 shots on targets line up horizontally as per the OP idea, what is then the difference between this and an OCW? This is of course being shot at longer distance i.e. 300 vs. 100 yards but with this, you are disregarding the laterals because of potential effect of wind so it seems like then you are getting closer to real life conditions i.e. longer distance but at the same time loosing some data?

The OCW method is fired "round robin" style, alternating between the increments and the targets for all shots.
In this scenario it would be 7 increments, 3-shots to each increment, at 7-targets. Which equals 21 re-positioned and re-aimed points of aim, spread over ruffly +21 minutes time.

The advantage of OCW over Group testing, is since they are fired incrementally, never firing a same increment more then once in a row, they incorporate unbiased fairness to fouling, barrel heat, and favored ambient conditions that Group testing can have bias and be victimized by, that can favor one group over another.

A 300yd OCW test from 7 increments, could easily be influenced and pushed around by wind to the triangulated group centers in the time frame it would take in using the method, unless shot in prestigious conditions. There for a 300yd Group test would have an advantage by firing all shots to each increment at one time and rapidly, with ability to "beat the wind" or at least fired in "similar wind" condition for each group. The bias to the Group test is which groups were fired in more favorable wind conditions, fouling conditions, etc..

Just my 2-Cents
Donovan

 

[jlow]

Donovan – I agree with you on this if the OP is in fact firing 3 rounds per group before moving to the next charge group, but the correct way for the OP to do this would in fact be to fire the round robin fashion - there is nothing in his setup that prevents this?

I understand the need for re-position and re-aim but even when I shoot a ladder with a gas gun, I have to re-position and re-aim anyway since my club does not allow shooting out of a mg and so each round has to be hand loaded. The other thing is since I don’t like my barrels to get overly hot when I shoot for groups, I wait two minutes between each round and so from that perspective, unless I hold aim for the whole ladder, which I pretty much cannot, I have to reposition and re-aim anyway. I mean do you really shoot the whole ladder in a short period without re-positioning and re-aiming?

 

[dmoran]

Donovan – I agree with you on this if the OP is in fact firing 3 rounds per group before moving to the next charge group, but the correct way for the OP to do this would in fact be to fire the round robin fashion - there is nothing in his setup that prevents this?

I understand the need for re-position and re-aim but even when I shoot a ladder with a gas gun, I have to re-position and re-aim anyway since my club does not allow shooting out of a mg and so each round has to be hand loaded. The other thing is since I don’t like my barrels to get overly hot when I shoot for groups, I wait two minutes between each round and so from that perspective, unless I hold aim for the whole ladder, which I pretty much cannot, I have to reposition and re-aim anyway. I mean do you really shoot the whole ladder in a short period without re-positioning and re-aiming?

jlow -

While I myself prefer distance for load development, and encourage single Ladder "ruff in" and multi-Ladder "fine tuning" at distance, I am only speaking for bolt-action rifles, being shot from a front rest/pod and rear bag. Typically with tuned or low poundage triggers, and from higher-end scopes that can easily spot there own shots (there are other alternatives to shot spotting).

Other type rifles, rests, and equipment, I myself have little experience with, and there for no suggestions either. With that said, with your gas-gun scenario, the advantages of my ways may not serve you as well. And no doubt you have determined what methods works best for you, which could easily be arbitrary to mine, since we are not developing with similar rifles or equipment.

Donovan

 

[jlow]

I did not mean to confuse the issue by bringing in the “gas gun”, but it does illustrate the problem with a lot of discussion on this board which is we discuss things here frequently like we all shoot the same type of guns /competition but the fact is we don’t and this and issues like annealing are frequently bogged down because of this.

But going back to even just shooting bolt action rifles, my AIAT is certainly a bolt action and the NF Beast on it is certainly a high-end scope but it certainly is not a BR scope and so even there we have distinct differences.

The idea that ladders appears to have to be shot “rapidly” with ability to “beat the wind” because of the significant distance to target would also distinguish it from an OCW where because by design i.e. shooting only at 100 yards, wind is not a significant factor.

Tom, how do you test 5 (I presume 5 ladders) with 1 POA?

 

[dkhunt14]

Yep SHARPIES are worth their weight in gold. Used for numbering cases to coloring bullets for identification on target. Matt

 

[dmoran]

The idea that ladders appears to have to be shot “rapidly” with ability to “beat the wind” because of the significant distance to target would also distinguish it from an OCW where because by design i.e. shooting only at 100 yards, wind is not a significant factor.

For claritification here:
I did not say that about Ladder Testing (high lighted in your quote)..........
Nor have I read anyone else stating that about Ladder Testing !.!.!

What I said pertained to Group Testing:
"There for a 300yd Group test would have an advantage by firing all shots to each increment at one time and rapidly, with ability to "beat the wind" or at least fired in "similar wind" condition for each group."

In my own Ladder tests and in my advise to them, I fire all shots at one common base-line to barrel temperature, and is the advise I always offer. Which are dependent on how many increments (shots) will be fired and barrel contours to how fast they may be shot. With big ladders and light contour barrels, I actually shoot ladders very slow (which is advantage in a Ladder, since lateral wind deflections have no effect to the assessments of a ladder like they so easily do at distance with Group or OCW).

Donovan

 

[IA_shooter]

Good discussion.

Just for the record I plan on waiting until I have absolute ideal conditions to go shoot. I plan on shooting each 3 shot group fairly slowly and letting the barrel cool back down between each 3 shot group for at least 3-4 minutes.

Thanks for all your thoughts guys.

 

[IA_shooter]

Definitely will work! I shoot 3 shot groups as you say individual targets on a horizontal plane so POI can be compared to POA easily on a three shot group versus a single shot on a ladder.

Start your charge weights @ 43 as there is usually a very good node @ 43.5

I've already done some initial testing in the 42.5 - 43.5 range and there was a very good node in the 42.6-42.8 area that gave me upper 2's, low 3's for 3 shot groups @ 100 yards. Now I want to see if there is a good node up higher with faster speeds is all.

A 3 shot group @ 100 yards.............

 

[DHuffman]

I've already done some initial testing in the 42.5 - 43.5 range and there was a very good node in the 42.6-42.8 area that gave me upper 2's, low 3's for 3 shot groups @ 100 yards. Now I want to see if there is a good node up higher with faster speeds is all.

A 3 shot group @ 100 yards.............

Yeah I get it. That's nice!

 

[Hondo64d]

Just curious if anyone is doing a ladder test/grouping test of several different charges at the same time? For example, what I mean by that is loading up 3 rounds of each charge like I'm doing for the 1st time to try this. I'm loading up 3 each of charges of 43.6, 43.8, 44.0, 44.2, 44.4, 44.6, and 44.8 of Varget to test some 175 grain Sierra TMKs in my 308.

I plan on shooting at fairly good sized cardboard backer @ 300 yards with seven different small targets all in a horizontal line so I can compare the fall/rise of the POI for each charge and see if any of these charges also group really well at the same time.

Good way to test or ? Should I load 5 of each? Thoughts?

Thanks.

I kinda combined a ladder and OCW at 500 yards.

John

 

[Dshooter]

^^^^ very crafty. I like that idea

 

[kyreloader]

I kinda combined a ladder and OCW at 500 yards.

John

What did you pick? 6 or 7??

 

[Buzz]

Just curious if anyone is doing a ladder test/grouping test of several different charges at the same time? For example, what I mean by that is loading up 3 rounds of each charge like I'm doing for the 1st time to try this. I'm loading up 3 each of charges of 43.6, 43.8, 44.0, 44.2, 44.4, 44.6, and 44.8 of Varget to test some 175 grain Sierra TMKs in my 308.

I plan on shooting at fairly good sized cardboard backer @ 300 yards with seven different small targets all in a horizontal line so I can compare the fall/rise of the POI for each charge and see if any of these charges also group really well at the same time.

Good way to test or ? Should I load 5 of each? Thoughts?

Thanks.

This seems almost identical to Cortina's method. He shoots groups with different POA but stresses the shift above/below the horizontal line is more important than group size in the first stages. There's a 60 or 70 page thread on the forum titled Long Range Load Development at 100 yards or something similar.