Second Opinion on Ladder Data

[PLeighton]

I'm working up a M118-LR Clone load and wanted to get a second opinion on the Ladder test data that I've collected so far.

Blue lines represent 1/2 MOA @ 500 yards.

The test was done at sunrise with a target puller down range.
(0-2mph for wind, no mirage)
Starting load was 42.0 grains of RE15, 175 SMK, 210M primer, & once fired LC LR brass.
The host rifle is an FN A5M SPR, so changing up seating depths is not an option.

Here is the test target in case anyone was curious.

I'm thinking that 44.5 is my OCW, but I would like to hear other opinions.

Thanks!

 

[kombayotch]

Re: Second Opinion on Ladder Data

#23-26 are clustering very close. I would pick #24 with the logic being that it is right between #22 and #26, vetically and horizontally.

An (x,y) location plot would be more meaningful...

 

[PLeighton]

Re: Second Opinion on Ladder Data

kombayotch,

I was hoping that you would chime in.
Didn't look at horizontal dispersion at all.

Thinking about doing another test using the round robin technique.
Jason Baney made some really good points in his write up.
http://www.6mmbr.com/laddertest.html
Three ladders @ 500 using 44.2 - 44.6 should provide a definitive conclusion.

One side note is that this load seems to be very dirty.
After 40 - 50 rounds, the patches are totally black.
Anyone notice the same thing with similar loads?

 

[kombayotch]

Re: Second Opinion on Ladder Data

Three would definitely give you a good confirmation. I still prefer the 100 yard OCW test. It has the 3 round redundancy built in and wind is much less of a factor.

With either test, your brass preparation needs to be meticulous in order for the tests to be repeatable. Second or third firing after annealing is where I get the best consistency in my loads.