Need some advice on these loads

[dirtking]

I went out and tested some loads in my 6.5 creedmoor this morning. They were all loaded with 140gr Berger hybrids, h4350, fed 210m, and 2.810 overall length. This put them about .100 off the lands. I didn't have a chronograph with me so I don't know the velocity. I shot 40, 40.5, and 41grs round robin. Let the barrel cool and then shot 41.5, 42, 42.5 round robin style. Looking for advice as where to go next.

And a pic of the rifle built by Keith at PCR

 

[dirtking]

Forgot to add that these were shot at 125 yards. Was hoping to be up in the 42gr range for the better velocity.

 

[pell1203]

40.5 looks pretty good! Might be tightening up from 40.0 and just beginning to start to open up 41.0. There may also be a smaller accuracy node somewhere at 42.2 to 42.3 range... but it is a little hard to tell and does not look as forgiving or consistent as the 40.5-40.7 range might be. Just my 0.02.

 

[dirtking]

Yea I agree on the 40.5 load shot extremely well. Was surprised to see it really opened up when getting up to the 41.5-42.5 where most people get killer results with it.

 

[Deadshot2]

Determining what load is best when only shooting 3-shot groups is frustrating for me. I prefer 5-shot groups. To me it gives a better feel for what the load is doing and those single shots that get out of line can be truly called "fliers".

I use the "On Target" program to analyze my groups and focus a lot more on the Average to Center measurement. I think my cost on it was about $12 for a registered copy. Good tool for load development.

On Target Precision Calculator

 

[17874]

I would try a ladder test at 300 and see what happens. I have had loads that would one hole at 100 and would barely give me MOA at distance. Get the accuracy at distance first and then see how it does at close range. Also, a chronograph would be a good thing to acquire for some good data on deciding a load. Ideally you get the hottest safe load in the node with a single digit SD and you are set.

 

[dirtking]

Ok thanks for all the advice. The place I have to really stretch the distance has very tall grass and cattle in it now so limited to the 125 yards right now. I didn't encounter any pressure signs yesterday so I loaded up a few more but these I only went up .3 gr. everything else was the same. I did retest the 40.5 gr load again to. These were shot round robin style again.

It baffles me that 42.5 was so big then 42.8 shoots one hole then 43.1 opens back up.

 

[pell1203]

You should not necessarily be looking for the tightest group at this point. You should instead be concentrating on where the majority of the bullets group relative from one charge weight to the other. If you look at 42.5 and 42.8 five of those shots (except for the 42.5 at 9 o'clock) are very tightly grouped so my guess is that there may in fact be an accuracy node very close to 42.8. Your 43.1 target also groups at about the same elevation but is beginning to perhaps show a bit more horizontal dispersion which could be due to an upcoming scatter node or a minor lapse in concentration on your part (hard to confirm without seeing the next charge weight beyond 43.1).

I am certainly not expert as I am just beginning to explore the OCW method myself, but based on my understanding of it, that is what I think may be happening here. I'll keep following this to see what you end up with. Good luck!

 

[dirtking]

Thanks for all the advice! I am gunna load up some more of the 42.8 load and take it out to some distance to see how it shoots. If not shooting well I will try the ladder test. I did remember the chrono this time and the 40.5 loads were averaging 2650 and the 42.8 was 2800 out of my 25" rock barrel.