Ladder test at 100 yards – no vertical!?

[thefitter]

Little background first, I have 2 loads for this rifle (N550 & N540) that shoot pretty consistent .25moa at 100 and 200 yards. Last week I chronographed both loads and discovered that the ES was 45 and the SD was 14 for both. I was not very happy with the prospects for long range performance of these 2 loads so I decided to try a ladder test and see if I could start to work towards identifying a load that would hold vertical at long range.

I did 4 ladder tests with all the same components but 4 different powders. I started 2 grains over book max and worked backwards in .2 grain increments in my loading for 10 rounds of each powder. (Obviously I started shooting at the lowest load.)

I put a small ½” red dot at the bottom of the paper. As I shot each round I plotted impact on a separate sheet of notebook paper. I was expecting to see a vertical string as I went up in charge weight like I see in other posted ladder tests. As you can see it’s not even close to the other ladders I have seen.

While there are some areas that look like they hold vertical better, this is just not what I was expecting at all. I have no idea where to go from here.

Also I should add that there were NO pressure signs at all. Weather was cold for here, 35-40 degrees Fahrenheit.

The only thing I really got from this is that N140 looks to be very promising at any weight.

Any ideas how to proceed would be greatly appreciated, thanks.

 

[jimbo88mm]

100 yards is too close for a proper ladder test. You really need at least 300 yards.

 

[thefitter]

That sucks. I only have 100 & 200 nearby. About an hour and a half drive to get farther out.

I would have thought I would see some vertical with charges of 2 grains difference.

 

[jimbo88mm]

Yea.. fortunately my go to range stretches out to 300. You can try it at 200, you'll defiantly get more vertical separation at 200 then 100 but 300-500 is best. Here is a the results from my first attempt at a ladder test:

The little trick of painting the tips of your bullets with different colored sharpies works! I used a white poster board. You have to push the bullet holes closed from behind but sure enough you can see the colors. Makes it very easy to see which charge printed which hole:

Ignore the numbers next to the holes, I was just measuring the distance from a witness line. Makes plugging in the data onto a excel spreadsheet easy and you get a nice little chart that in theory shows you where your nodes are.

 

[necchi]

That sucks.

Yeah, that's alot of shooting to prove nothing huh?

Look's like the N550 is your best

 

[thefitter]

That sucks.

...Look's like the N550 is your best

Why do you say that?