Help to Decipher Ladder with 124 gr Hammers

[Lpart]

Went to range with new build in 6.5CM twice today. Shooting 124 gr Hammers. First pic is a seating depth test using 42.2 gr H4350. Not a huge difference. I think the last one at .080 off lands to be slightly better and I used that for the ladder test. Any thoughts? This seating test was done at 100 yards.

Then did a ladder with H4350, 41.6 to 45.2 gr in .4 gr increments. Not much of a ladder to me. Shot at 300 yards which is all I had available. I forgot in include a scale in the pic. Distance from #1 to #8 is 2 inches. Width from #1 to #9 is 5 1/2 inches. The group with shots 2-5 and 7 is 3/4" wide and 1" high. Not sure about the horizontal dispersion. No wind and I was dead steady on bags.
Shot string follows:

#1 41.6 gr 2827 fps
#2 42.0 gr NR
#3 42.4 gr 2889
#4 42.8 gr 2930
#5 43.2 gr 2933
#6 43.6 gr 2900
#7 44.0 gr 2945
#8 44.4 gr NR
#9 44.8 gr 2998
#10 45.2 gr 3023

No signs of pressure until shot #10. Then only a very slight ejector mark that was barely visible.
I am not hell bent for leather on the last bit of velocity so I'm thinking it looks like a node at 42.8 to 43.6. Do you fellas agree with this or where am I missing the boat please?

I just picked rifle up from gunsmith yesterday. Completely reworked Rem 700, heavy duty lug, Bartlein #4 24" 5R barrel, speedlick firing pin, Jewell trigger at 1 1/2 pounds, Wyatt BDL extended magazine box and Iota Kremlin stock. Topped with NF 2.5-10x32.

I appreciate any guidance you are able to give me.

 

[cape cove]

Your group .040 off the lands looks good except for the one flyer. Was this a pulled shot. I believe I would have worked from this group. just my opinion.

 

[Mike 338]

Like you said, it's not much of a ladder. People need to stop doing ladder tests at short range. What you have is the equivalence of doing bench presses as a pregnancy test. Your gonna have to move back quite a ways to get any real data if a ladder test is what your doing.

 

[L.Sherm]

Why did you do the seating depth at 100 and powder at 300 should have done them both at 300. I would try that 43.2 powder charge and seating depth ladder at 300 yds. Minimum or farther.

 

[Mikecr]

I like it.
I would now work powder in #4 to 6 range(like you said), at 300, and tweak seating there within +/- ~10thou for best group shaping.

You might also do some pin setting testing. There may be a best released pin protrusion for your chosen primer. This, removing flyers.

 

[Gord0]

I think your seating test at .04" off looks the best. Horizontal doesn't bother me much when I'm running a seating test, or ladder. Your ladder looks like you have something else going on. They're kinda all over the place.

 

[Mikecr]

Many ladders widen & narrow both horizontal and vertical(like OP's).
IMO, both are just as important.

Consider #7 & 8 loads on his target. That's low vertical.
If he chose something there, he'd rarely get 5 shots together in a group. Probably end up consistently/impressively double grouping..

 

[ChrisInKY]

Your ladder looks like you have something else going on. They're kinda all over the place.

+1