Long range load development at 100 yards.

[Erik Cortina]

Hello,

Ok, going to delete first post and start a new one to clean it up...This time I have included a "table" of my chrono info, I have also attached a excel graph as well.

Been a lurker for quite a while...I have decided I want to just try some 1000 yard stuff near me. 300 wsm, 24" barrel, 208 Amax. This test was using H4350, I am a little confused on the results and looking for some direction. Last charge (62.5 gr) was not showing any pressure signs, do I load a few more to find max pressure? Or do I just use what I have to start finding seating depth? If so, 62 & 62.5 seem to be on the same vertical...so I would pick 62.5, correct?

GRNS 59.5 60 60.5 61 61.5 62 62.5 MV 2721 2741 2745 2777 2801 2808 2824 ES 67 12 19 35 23 29 18

roklock, there is really no pattern to your groups. I would suggest doing another test perhaps with higher charges since you said you encountered no pressure signs. Load groups in incremental powder charge and stop when you see pressure signs. I usually load enough to take to the range that would get my past max but I won't shoot them if pressure is encountered. I would rather pull bullets than make another trip to the range.

 

[roklock]

I would suggest doing another test perhaps with higher charges since you said you encountered no pressure signs. Load groups in incremental powder charge and stop when you see pressure signs.

Ok, I will do that, I have also have RL 17 loaded to try as well. First time I have ever loaded "long" (past SAAMI) (I'm .010 off lands) but I was sure 62.5 was going to be near or past max pressure based on what I was reading.

 

[glockaholic]

Hi Eric,
Round 2: This time with Varget and 140gr Hybrids. Your system works good!
The first image is the load workup from 36.5 to 41. I didn't shoot higher than 39.0 due to pressure signs.
grains 36.5 37.0 37.5 38.0 38.5 39.0
avg 2741 2787 2803 2842 2890 2915

The second image is the seating depth workup from .000 to .025 jump while using 38.0 gr.

Thanks for your help, .....Carl

 

[Erik Cortina]

Hi Eric,
Round 2: This time with Varget and 140gr Hybrids. Your system works good!
The first image is the load workup from 36.5 to 41. I didn't shoot higher than 39.0 due to pressure signs.
grains 36.5 37.0 37.5 38.0 38.5 39.0
avg 2741 2787 2803 2842 2890 2915

The second image is the seating depth workup from .000 to .025 jump while using 38.0 gr.

Thanks for your help, .....Carl

Carl, you did not follow my instructions. When doing seating depth, I say to do testing in .003" increments. You started that way but then went to .005" increments. -.020" shot well, but you do not know how wide your node is precisely because -.015" and -.025" did not shoot well. At -.020", you do not know if you are on the edge of the node or not, which is not a good thing.

 

[glockaholic]

I didn't have that many cases ready. I'll do more between .015 and .025.

 

['Freak]

I'd stay with 61 grains and work with seating depth that seems to show the least verticle. What distance where these shots taken at

100 yards...but I am confused 61 is lower than 60.5 but higher than 61.5, where 62 and 62.5 seem to be at the same vertical.

The impact on paper don't mean squat as for aim point and impact, you can actually in some instances see a higher velocity impact lower than. A slower. This is due to where the bullet exits the barrel in the harmonics of the barrel. What I'm looking for here is the least amount of verticle between the targets you posted and it appears 61 shows the least verticle.

I am trying to follow Erik's program so I am trying to understand how does this follow Erik's rules on the first page of this post? It says to look at groups in the same vertical, not shots?

5. Shoot 3 shot groups starting from lowest to highest. All groups are shot over a chronograph.
6. Examine target and find the place where consecutive groups line up vertically and ES is the lowest and speed increases the least from one group to the next.

Thinkin’ “where consecutive groups line up vertically” means the impacts align horizontally, side by side, or are generally all at the same height relative to the aiming point, and not stacked so forming a vertical column.

 

[BradY]

Moderators- not sure if its been mentioned but this might be a good topic for a 'sticky' post.

 

[william5409]

WOW!!! Great!

 

[fspitzdorf]

OK I'm back for another round. Same rifle, my 1941 USMC Sniper clone. This time I come bearing more than targets after finally breaking down and replacing my magnetospeed. Let the fun begin.

I fired the first set of targets but had a few issues through-out the string with a few erroneous impacts due to some trigger malfunctions that arose. I tried to mark the notable ones. I collected data regardless.

Target and raw data as written down.

After taking care of the trigger issues I went back and re-ran the test again. This time I stepped the load up a bit more since a single 59 grain test load showed no pressure signs and I wanted to push it a bit further to find the threshold. Even at 60.0, which is very compressed, it was still showing nice round primers and no cratering...

Round 2 raw data and targets...

I decided to combine both sets of chronograph data and do some analysis. For the distance to center plots I used the data from the 2nd set of targets only. For the standard deviation, average velocity and average velocity gain between charges I used all chronograph data.

Hopefully that is enough information to take the next step. One thing I don't understand is the difference between the 58.0 group between trials one and two.

 

[Erik Cortina]

fspitzdorf, I would take 57.0 and adjust seating depth. After you get best seating depth with 57.0, go back and test powder charge in .1 gr. increments from 56.5 - 57.5

 

[Marksman63]

Erik, looking at that vertical graph, I would have chosen 56.5.
Just to better understand your suggestion, does your 57.0 consider the speed difference as well, balancing the two results?
Thanks,
Amleto

 

[Erik Cortina]

Erik, looking at that vertical graph, I would have chosen 56.5.
Just to better understand your suggestion, does your 57.0 consider the speed difference as well, balancing the two results?
Thanks,
Amleto

If you notice I suggested that he test again after his seating depth is completed. I think his node is somewhere around 56.8 but powder charge testing after seating depth optimization will confirm that.

 

[Marksman63]

Roger, thanks!

 

[Brians356]

Just to better understand your suggestion, does your 57.0 consider the speed difference as well, balancing the two results?

+1

A chance to better understand the nuances for myself as well.

 

[Erik Cortina]

Just to better understand your suggestion, does your 57.0 consider the speed difference as well, balancing the two results?

+1

A chance to better understand the nuances for myself as well.

57.0 was consistent on speed on both, but I'm not 100% confident that that will be the correct charge, that's why I suggested further testing after seating depth.

 

[Brians356]

4. ... I load 4 of each powder charge in 0.5 gr. increments and seat bullets at jam - .020". I use one shot of each to get barrel fouled up and also keep an eye for max pressure at the same time.

Erik,

I'm sure it's obvious to most, but do you shoot all the foulers (one from each charge group), in progressive order, at the beginning of the session, and if the hotter ones show adverse pressure signs, you know not to bother recording the associated groups?

 

[Erik Cortina]

4. ... I load 4 of each powder charge in 0.5 gr. increments and seat bullets at jam - .020". I use one shot of each to get barrel fouled up and also keep an eye for max pressure at the same time.

Erik,

I'm sure it's obvious to most, but do you shoot all the foulers (one from each charge group), in progressive order, at the beginning of the session, and if the hotter ones show adverse pressure signs, you know not to bother recording the associated groups?

I shoot the fowlers in progressive order until I see pressure signs and to find max charge. I don't bother shooting the groups above max load.
BTW, I use culled brass for this test since I will be hammering on brass to find max pressure.

 

[minnesotamulisha]

Hi Everyone. I shot a group of IMR 4166 and 155 TMKs and had Erik determine that the node was around 44.8 grains. I determined that the distance to the lands of my rifle is 2.218". I then did a depth test at the following CBTOs:

2.208
2.205
2.202
2.199
2.196
2.193
2.190
2.187

Here are the results:

The shots that are circled in RED are two shots. There four groups like this. Should I shoot the groups with red circles again and choose from those groups? Not sure how to move forward.

Thanks for all the help!

 

[dmoran]

Looks to me like you didn't start close enough and suspect that from 0 to 10-off is where best will be.
Your 2.208 impresses me the most that is "flat-lined" vertical, and suggest to test IN from 2.208 in smaller increments.
My 2-Cents
Donovan

 

[minnesotamulisha]

Thanks Donovan. My only concern is "chasing" the lands if I go much smaller. Should I test two groups on each side of 2.208? Or maybe just 2.211, and 2.214 on the top side?