Ladder - 10 shots 41.9 to 45.5gr all < 1 MOA!?

[johnsopa]

OK, guys, I need some help from you experienced long-distance reloaders, especially those that use ladder testing.

In the past, I typically use an OCW-style round-robin test to get a good load, then if it shoots around 1/2MOA for 5x5 groups at 200 or 300 yards, I just go with it.

I got a box of Hornady's new 6.5mm 123gr AMAX bullets for my Savage with a 260 Rem barrel (Shilen). Read through my load books and did some playing with Quickload and decided on a starting load of 41.9gr of H4350 with a max load of 45.5gr.

I decided to do an initial basic ladder test using 0.4gr increments. So, I loaded two 41.9gr foulers and one each of:
<div class="ubbcode-block"><div class="ubbcode-header">Code:</div><div class="ubbcode-body ubbcode-pre" ><pre> 41.9
42.3
42.7
43.1
43.5
43.9
44.3
44.7
45.1
45.5
</pre></div></div>
I was hoping to shoot this ladder at 500 yds but that wasn't available. So, I had to settle on 200 yds. I know this is not ideal for ladder testing but I wanted to at least get an indicator of where I should look for a more granular load test for the next round.

I was surprised that all 10 shots went into 1 MOA at 200 yards. I wasn't expecting this at all.

It does look like there might be a node somewhere between 43.5 - 44.3gr (shots 5, 6, 7) and **maybe** there is one starting at 45.1 - 45.5gr (shots 9 and 10). I was not seeing any pressure signs at 45.5gr.

Anyway, based on what you more experienced ladder testers see with this, do you thing there is any worthwhile data in this, or should I simply retest (maybe starting with my #4 load and going a bit higher than 45.5gr) at 500 yards?

 

[Grump]

Re: Ladder - 10 shots 41.9 to 45.5gr all < 1 MOA!?

Disclaimer: I do OCW, not Ladder Testing.

That said, I believe that recoil dynamics and barrel harmonics could be masking the utility of your results there at 200. If you were developing a load for 200 yards standing SF and sitting sustained-fire for over-the course, I'd say just pick the velocity you want from those loads (probably lighter) and just throw your charges.

The bullet and rifle combo is VERY charge-weight tolerant at the 1 MOA performance standard at 200, and probably back in to the muzzle. Perhaps even out to 300. Without velocities, can't make a reasonable estimate.

Sample sizes of one provide only faint clues for further development, not real evidence of a node anywhere. Too much possible statistical "noise" there, unless your rifle and that bullet shoot .25 MOA or less, but even then you could have a bad load that failed to produce a flyer with that single shot.

 

[bigwheeler]

Re: Ladder - 10 shots 41.9 to 45.5gr all < 1 MOA!?

I would load up one batch ( 5 or 10 rounds) at 43.7 and also another round for
ladder testing. Shoot the 43.7's first and if they don't pan out shoot another ladder
test and see if the results are the same. If they do pan out, take the ladder test rounds home and pull the bullets.