Thread: Interpreting a Ladder Test

Interlocks are cheap and you can get them closer to the lands than sst in mag fit.

Originally Posted by Toby

Nosler are expensive. Only thing that put me off for my new 6.5

Your not wrong Toby

I like them but being a confirmed Tight Arse doesn't sit well with me when I can got to the Hornady range for half the price.

Cheers
Pete

I have Wile staying in my hut, he is a wealth of reloading knowledge, I will ask him a good 308 150 grain load , I think he is shooting 125 and 130 grain in his 308

Id be loading both at 47.4 and doing groups then playing with seating depth if needed

Sent from my GT-I9300 using Tapatalk

I looked over these results last night and tried to interpret them as best I could and then decided on the following

Hornady 150gr Spire points best grouping was around 47.5grs

Hornady 150gr SSTs best groupings were around 46.5gr and 47.4gr

So I loaded up 5 of each of these and went back to the rage today with the following results.


The end result is 47.5grs of W748 with the 150gr spire points and 47.4grs of W748 with the 150gr SST's is looking good.

Might end up settling on 47.5grs W748 for both projectiles and adjust the seating depth to see if I can close the groups down even more.

Cheers
Pete

I tried to do a ladder test working up a load for my 223 had 10 bullets of different powder weights all go into less than a 2" group at 100m lol. I threw the target away and just did it the normal way, as my test suggested anywhere between 25 and 26.5gr of powder would do.

I think ladder tests are meant to be done at longer ranges, that way you aren't looking at half a millimetre difference, and results should be a bit more obvious.

Originally Posted by Beetroot

I tried to do a ladder test working up a load for my 223 had 10 bullets of different powder weights all go into less than a 2" group at 100m lol. I threw the target away and just did it the normal way, as my test suggested anywhere between 25 and 26.5gr of powder would do.

I think ladder tests are meant to be done at longer ranges, that way you aren't looking at half a millimetre difference, and results should be a bit more obvious.

Beetroot

That's kinda what happened here.

I'll try those loads at 200m in a week or so and see if I can repeat this result.

Cheers
Pete

P38 I'm a bit lost here on the ladder test thing, what are you looking for? The only time I do a single shot test is to check for pressure, I don't care where they shoot on paper, when I shoot 3 or more of the same load I still don't care where they shoot relevant to the point of aim but how close they are together.
I'm obviously living in the stone age and need some education about this ladder test thing. As I said to Brian a few days ago in a perfect world every shot should rise a1/4 of an inch per 1/2 grain of powder in a direct vertical plane.

Cheers

looking for accuracy nodes within a small powder variance, e.g 30.2 30.4 and 30.0 might all be close meaning that is the accuracy node, can do the same by keeping the sme powder charge and changing seating depths ect.

IMO a waste of time doing it unless its done at 200m+ an with a rifle/shooter combo that is pretty bloody accurate allowing you to interpret results.

Originally Posted by PerazziSC3

looking for accuracy nodes within a small powder variance, e.g 30.2 30.4 and 30.0 might all be close meaning that is the accuracy node, can do the same by keeping the sme powder charge and changing seating depths ect.

IMO a waste of time doing it unless its done at 200m+ an with a rifle/shooter combo that is pretty bloody accurate allowing you to interpret results.

I think 300m is the typical distance for these tests, definitely not 100m.
The wind usually doesn't matter either as it's really the vertical spreads/nodes you look for.

Just to muddy things further what about doing it this way

OCW Overview - Dan Newberry's OCW Load Development System

Originally Posted by mikee

Just to muddy things further what about doing it this way

OCW Overview - Dan Newberry's OCW Load Development System

Very interesting Mikee.

Thanks for this.

I do seem to remember reading this quite some time ago but had forgotten all about it.

It would be interesting to complete an OCW on my rifle with these 150gr projectiles and see if we arrive at the same conclusion as I already have.

Cheers
Pete

Originally Posted by P38

Very interesting Mikee.

Thanks for this.

I do seem to remember reading this quite some time ago but had forgotten all about it.

It would be interesting to complete an OCW on my rifle with these 150gr projectiles and see if we arrive at the same conclusion as I already have.

Cheers
Pete

I would be interested in your results too. I would be worried about getting a shot "out of sequence" but it sounds logical

Using the ladder test at 100m or 200m is hard to interpret there is not enough distance between shots, I use a variation of the OCW I had problems with the round robin system (short attention span) The way I do it is to load powder in increments of .3grains and shoot groups of 3 at 5 targets at 100m and compare the results as Dan Newberry describes, start load is a least 2.0 grains under factory max
and bullets seated to manufacturers specification in the case of .308 at 2.800" usually can get an acceptable load first time, if the pressure sign are ok keep increasing the powder charge until you reach max, It helps if a good brenchrest set up is available then you can repeat the test at 200m with the best loads, if you want to see how good your rifle shoots buy a box of Federal Gold Match 168gr
it is the standard load used by most US Police snipers and Remington test their Match rifles with it, a good way to set a benchmark for you reloads, a load I find shoots well in most .308's is 43.6grs of 2206H and a 150gr Hornady Spire point, it's quite mid and very accurate. Robert.

Hi P38. To make it easier for me I numbered your shots. Statistically there are no patterns here, just data that says that ladder testing will not give you the information you are wanting.
Both ladder testing and the OCW method are intended to identify barrel vibration "nodes" as a means to reducing the effect of shot-to-shot variance in a given ammunition. My interpretation of this target is that other factors in your set-up are setting the overall group size, masking the information that the ladder test may otherwise provide. They will do the same thing for OCW testing.
My best advice if you are wanting to shoot smaller groups is to pass on ladder & OCW testing and shoot test groups with each type of bullet that are acceptable for the task you have in mind and hope that one or more of these meets your expectations, sticking with a moderate load for each, 7-shot minimum groups to get a bit of statistical significance. Good luck.