ladder test fluke

[earl39]

this is a 338-06 and did a ladder test today and got some strange results ( need to rotate pic 90 degrees)

lake city brass
hornady 225 sst
cci br primers
varget powder
range 300 yards with slight downhill angle
winds light but gusty
temp was in the low 90's
humidity about 70%

started my loads at 48.1 gr and increased .3 at a time. everything seemed to be going good until shot 5. notice shot 3 and 5 are touching as are 9 and 7 also notice 4 dropped out as did shot 8.
i have had problems with varget not wanting to shoot for me in my 308. should i change powder and try again or am i missing something else. bullets are all loaded at the same setting so only the powder charge has changed. i let the barrel cool however long it took me to ride to target on 4-wheeler after each shot and mark the target. with the wind i was mainly looking for elevation but this is just strange.
the red dots were sighters to get me on paper

 

[jo191145]

Somethings not happy!!!

I've been fiddlin with my first 30BR for 5 months now. Shot a whole bunch of Audettes at 200yds that would equate to something like that at 300. Different bullets, seating depths, powders, primers, Neck sized, FL sized, turned a little extra off just in case. Switched scope, bases, rings, action, stocks. Everything I could think of. Everything looked like that. Groups tried were 1-2 moa for the most part.

Today for the first time I deviated from the prescribed .004" recommended neck tension and tried .0015". Bingo, Its shootin .1 up to.5 moa at 200 with an arbitrary load of RL-7 and stinkin Sierra 110 varminters consistently. Now I can spend money on some real bullets and start over.

All that just to reiterate, somethings not happy. Not suggesting neck tension is your culprit. From everything written about the 30BR its load and shoot. Mine must not be able to read well ;D
Good Luck

 

[Kenny474]

What magnification is your scope? I am not sure about a 338-06, but my 30-06 loves H4350.

Also, how far from the lands are you?

 

[earl39]

had scope set on 20 as for how far off the lands i haven't tried to get close except with 250's but just a guess would put me about 40 thousands off but don't hold me to that. what got me was the 2 in 1 twice with the load between each of them dropping out. how do you figure a ladder with that happening? so the real question is do i do the test again as is or change powder and then try it again? and what would cause the dropouts?

 

[necchi]

I'd run the test again, BUT, using a tighter increment, .1 grn for each increase, and beggining with your shot #6 (49.6grns) and running up to shot 10. This is considering you had no pressure signs. Pick a calm day to shoot or at least one with a steady wind.
Your shot's 4 and 8 could have dropped out because of a gust at 275yrds that you didn't see or feel. 7 and 9 where nice and close so that's what your looking for, at least it's some kind of group in the higher velocity range.
Again, I'd run it again but at the higher end of the powder charge range.