Range Report ladder test // nodal tuning WORKS!!!!! pics added

[Mag 300]

I just had a chance to perform some ladder testing for two Tubb rifles one in 6 cm and the other in 6xc
I made 2 each of the loads spaced .3 grains apart for each of the bullet combinations. 3 in all and 6 targets used

its a tedious task at 300 yds walking back and fourth but shot each at a single target there fore getting two ladders for each load. again there were 3 loads 2 for each powder charge and 6 6 targets for the test.
I will post pics tomarrow night but there is a clear pattern for the loads. I happen to see a good consistance for three loads that covered .9 gr total change this leads me to loading in that area for a smaller more defined test.
if you have not done this try it Hightly suggest that you have some one to mark the target after you shoot I did not and second use a scope I also tried this using iron sites at 300

beleive it or not you still get a rreading of what the barrel likes even with the irons

here is the 6cm pic at 300 yds

here is the 105 scenars at 300 first target

here is the 6 XC with 105 scenars at 300 IRON SITES

second target

it seems that the #4 5 and 6 are the best of both
Bill

 

[Casey Simpson]

Re: ladder test // nodal tuning WORKS!!!!!

Thank you, Bill; look forward to the pictures.
I used it this Summer but next time I'll put a buddy in the pit and have him number shots, or use the multiple target way.

 

[PLeighton]

Re: ladder test // nodal tuning WORKS!!!!!

For those that want to learn, here is a link to Jason Baney's article:
http://www.6mmbr.com/laddertest.html

After doing my own research, I have found this article to be one of the best.
It covers pretty much everything and most importaintly, it gives a clear description of how to do a "round robin" ladder.
The "round robin" enables you to have complete confidence in your results and I would highly recomend trying it.

 

[kombayotch]

Re: ladder test // nodal tuning WORKS!!!!!

I have a friend who uses that marker method to keep track of his groups without having to go back and forth to the target. Give it a try. Just color the bullets with markers and fire them at white paper. You can see the color ring around the hole and you will save yourself a ton of walking.

The beauty of the 100 yard OCW test is that you don't need to mark shots since each charge weight is fired at a different target. OnTarget software makes it easy to compare POI between the targets. Plus, it is less affected by things like wind.

 

[BLAWTON]

Re: ladder test // nodal tuning WORKS!!!!!

Im putting together a camera system that you can use a wireless setup to put a monitor or some type like a labtop at your bench and you never have to worry about knowing whats going on again. Great way to sort brass and prep for long range BR and other comps. Gives you a edge! Working up a load at 100 yards is not the answer unless thats where your gonna be shooting all the time.

 

[Mag 300]

Re: ladder test // nodal tuning WORKS!!!!!

addded the pics and thanks for the link to the round robin method

Do appreciate any feedback other than " yes I know I suck at shooting"
Thanks Bill

 

[GuinnessNM]

Re: ladder test // nodal tuning WORKS!!!!!

I think you will need to fire a lot more rounds for each load to have a valid comparison. Firing just a few two-shot groups you will only see statistical fluctuation in the group size. See this thread
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1312910#Post1312910

Recently I did a comparison of a few 308 loads by firing 4 5-shot groups (20 rounds) for each load, averaged the sizes of the 4 groups, and calculated the standard deviation of the group size, with these results:
Load___________Average size______St Deviation of avg. size

BHA 175gr SMK_______.62"____________________.13"
2580fps

175 gr SMK__________.60"____________________.08"
45gr Varget
2670fps

155gr Berger________.55"____________________.08"
46.8gr N150
2790fps

The smallest group was .4" and the larges was .91". This is completely consistent with the expected statistical variation.
Since these averages are all within 1 standard deviation of one another, there is no statistical difference. I would call them all .6MOA loads at 100 yards. The measured SD of the average size is about 20% of the average size, so one cannot distinguish loads which are less than 20% different.

Note this is not the SD of the group sizes, it is the SD of the average size (which is smaller). For 4 group averages the SD of the average is about half (1/sqrt(4)) the SD of the group sizes.

I also compared some 223 loads and the results for 5 5-shot groups (25 rounds per load) were:

Load_____________Average size______St Deviation of avg. size
BHA 77gr SMK_________.79"______________________.11"
2775fps

77gr SMK_____________.87"______________________.16"
23.6gr TAC
2780fps

77gr SMK____________1.06"______________________.13"
24.0gr TAC
2815fps

These loads are all within 1 SD of .9". In an earlier test I got slightly smaller groups with the 24gr load, so it's slightly worse grouping this day is probably just statistics, or maybe one flier. I would have to fire 4x as much ammo (100 rounds per load) to reduce the SD's a factor of two.

 

[Unsichtbar]

Re: ladder test // nodal tuning WORKS!!!!!

I shot ladder test for decades but not since I found the OCW method. For me better results, less work ( its done in about 25 rds)repeatable in test varification. Might take a look at Kobayotch post that he does OCW but including his pressure trace readings.

www.optimalchargeweight.embarqspace.com/ and http://practicalrifler.6.forumer.com/viewtopic.php?p=726&sid=edac31d853b32f50a7c9d55aee9a475d has alot of loads that might be of help

 

[Mag 300]

Re: ladder test // nodal tuning WORKS!!!!!

Some great reading here I will give it a try
Thanks Bill