• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

Long range load development at 100 yards.

comagutsa said:
new powder time

2208/varget with 105gr berger hybrids at .010 off lands (1st time using hybrids), target at 200m , 6BR, CCI BR4 primers, .272 no turn neck, loaded round 269, using 267 bushing with, .105" free bore, lapua brass





ok these are all 4 shot groups, speeds taken with magneto speed v3, there was a small amount of mirage and slight wind

29.6gr
min 2852
max 2864
avg 2858 SD 5.0

29.8gr
min 2863
max 2878
avg 2872 SD 6.8

30gr
min 2879
max2894
avg 2884 SD 6.8

30.2gr
min 2901
max 2917
avg 2905 SD 7.5

30.4gr
min 2913
max 2918
avg 2916 SD 2

30.6gr
min 2936
max 2945
avg 2939 SD 4.1

30.8gr
min 2953
max 2983
avg 2969 SD 12.6


any help would be great and then i will start seating depth

cheers
Pethy

I think I would load 29.9 gr.
 
bsumoba said:
If you are shooting groups with the magneto on, you might want to remove it as harmonics may have changed with it on.

Yes. Actually, I would suggest that he did his seating depth testing with the magnetospeed off.
 
Erik Cortina said:
Can I ask why is that Eric. Just trying to get my head around it as they have a bit of vertical?
I thought around 30.4 to 30.6 as they had the less speed difference or is it because the SD was 6.8 for both 29.8 and 30?

Oh yeah magneto wont be going back on as I have my speeds now
 
I find that in two of my rifles, POI is shifted almost 1 MOA low with the Magneto on. Groups open up a bit as well.

I typically look for a good accuracy load first, then whatever that is, I will then magneto it. I usually load on the higher end node anyway so chances are my velocities will be where I typically see others running that particular cartridge.
 
comagutsa said:
Erik Cortina said:
I think I would load 29.9 gr.

Can I ask why is that Eric. Just trying to get my head around it as they have a bit of vertical?
I thought around 30.4 to 30.6 as they had the less speed difference or is it because the SD was 6.8 for both 29.8 and 30?

Oh yeah magneto wont be going back on as I have my speeds now

Its because 29.8 and 30.0 have the same group centre. It would be worth shooting 29.8, 29.9 and 30 with magneto off and ensuring the group centres stay horizontally aligned. You will most likely find the group shape changes but you need to ensure the group centres still follow the logic.

i.e. if you did what I suggested I'm expecting 1./ group centres to run on the same horizontal as each other 2./ group shape to change 3./ POI for groups to be different to the test with it on.

It is entirely possible for the magneto to influence to both the negative and positive so it is worth validating.

Initial testing I have completed with the magneto on under this methodology I have found that I can get good groups but the group centres seem to move around a lot more from one charge to the next, making it hard to make a choice. Whether this is the magneto moving marginally each time I'm not sure.
 
Erik, I posted the chrono data from my testing back on page 97. I was wondering if you would still load between 77.5-78 and 76-76.5 or does the chrono data tell you otherwise?
 
I tried some Berger Hybrids and selected 37.5 for the seating test. Right choice?
 

Attachments

  • 140 Hybrid.JPG
    140 Hybrid.JPG
    46.9 KB · Views: 236
If velocity is where you want it, I would load another test from 36 to 38 using smaller increments of powder charges. Should show the full load window. Just my thoughts
 
P3S said:
I tried some Berger Hybrids and selected 37.5 for the seating test. Right choice?

I would load maybe at 37.4. 37.0 also looks good but the ES appears to be high.
Do seating depth test and see how it shoots.
 
MathewsSB said:
Erik, I posted the chrono data from my testing back on page 97. I was wondering if you would still load between 77.5-78 and 76-76.5 or does the chrono data tell you otherwise?

Can you please post it again along with the target?
Thanks.
 
MathewsSB said:
Erik, here is the chrono data from the test. i can give u shot by shot speeds if that would help.

charge avg velo ES
75.5 2731 39
76 2756 17
76.5 2783 35
77 2802 35
77.5 2828 6
78 2919 19
78.5 2931 13
79 2936 13
79.5 2971 26

i didn't get chrono data for 80 and 80.5 because i tested them later and had already put the chrono away but they didn't appear to be the right node anyway so i wasn't too concerned.
i liked 78.5 as a starting point because of the consistent speeds between 78, 78.5 and 79 along with relatively the same ES between the 3. the vertical between 77.5 and 78 appears a little better but not sure about it with the almost 100 fps jump between the 2. but i'm new to this and not sure what is best so i'm open to help

Here it is Erik. I appreciate the help
 

Attachments

  • 20150315_132733.jpg
    20150315_132733.jpg
    179.7 KB · Views: 100
6BRinNZ said:
comagutsa said:
Erik Cortina said:
I think I would load 29.9 gr.

Can I ask why is that Eric. Just trying to get my head around it as they have a bit of vertical?
I thought around 30.4 to 30.6 as they had the less speed difference or is it because the SD was 6.8 for both 29.8 and 30?

Oh yeah magneto wont be going back on as I have my speeds now

Its because 29.8 and 30.0 have the same group centre. It would be worth shooting 29.8, 29.9 and 30 with magneto off and ensuring the group centres stay horizontally aligned. You will most likely find the group shape changes but you need to ensure the group centres still follow the logic.

i.e. if you did what I suggested I'm expecting 1./ group centres to run on the same horizontal as each other 2./ group shape to change 3./ POI for groups to be different to the test with it on.

It is entirely possible for the magneto to influence to both the negative and positive so it is worth validating.

Initial testing I have completed with the magneto on under this methodology I have found that I can get good groups but the group centres seem to move around a lot more from one charge to the next, making it hard to make a choice. Whether this is the magneto moving marginally each time I'm not sure.

Cheers mate. I'm following you. Will post up results
 
MathewsSB said:
MathewsSB said:
Erik, here is the chrono data from the test. i can give u shot by shot speeds if that would help.

charge avg velo ES
75.5 2731 39
76 2756 17
76.5 2783 35
77 2802 35
77.5 2828 6
78 2919 19
78.5 2931 13
79 2936 13
79.5 2971 26

i didn't get chrono data for 80 and 80.5 because i tested them later and had already put the chrono away but they didn't appear to be the right node anyway so i wasn't too concerned.
i liked 78.5 as a starting point because of the consistent speeds between 78, 78.5 and 79 along with relatively the same ES between the 3. the vertical between 77.5 and 78 appears a little better but not sure about it with the almost 100 fps jump between the 2. but i'm new to this and not sure what is best so i'm open to help

Here it is Erik. I appreciate the help

Load at 77.5 gr. Based on the chronograph numbers, 77.0 - 77.5 look good. Any chance your chronograph is not reliable as the numbers appear to be off?
 
Erik Cortina said:
MathewsSB said:
MathewsSB said:
Erik, here is the chrono data from the test. i can give u shot by shot speeds if that would help.

charge avg velo ES
75.5 2731 39
76 2756 17
76.5 2783 35
77 2802 35
77.5 2828 6
78 2919 19
78.5 2931 13
79 2936 13
79.5 2971 26

i didn't get chrono data for 80 and 80.5 because i tested them later and had already put the chrono away but they didn't appear to be the right node anyway so i wasn't too concerned.
i liked 78.5 as a starting point because of the consistent speeds between 78, 78.5 and 79 along with relatively the same ES between the 3. the vertical between 77.5 and 78 appears a little better but not sure about it with the almost 100 fps jump between the 2. but i'm new to this and not sure what is best so i'm open to help

Here it is Erik. I appreciate the help

Load at 77.5 gr. Based on the chronograph numbers, 77.0 - 77.5 look good. Any chance your chronograph is not reliable as the numbers appear to be off?
As far as i know it is reliable. I did have different brass for the groups from 78 through the end. I didn't think that would cause a jump like that though would it? I'll go ahead and load up 77.5 when i get a chance and proceed with seating depth
 
I thought brass could vary in interior volume, which could lead to pressure differences, I will be interested in the informed responses.
 
Ed333 said:
I thought brass could vary in interior volume, which could lead to pressure differences, I will be interested in the informed responses.
if this is the case, i can rerun charges from 77-80 to check for consistency and will use the same brass from the first portion of the test
 
MathewsSB said:
Ed333 said:
I thought brass could vary in interior volume, which could lead to pressure differences, I will be interested in the informed responses.
if this is the case, i can rerun charges from 77-80 to check for consistency and will use the same brass from the first portion of the test

Do the seating depth test first and then go back to powder charge in .1 gr. increments to pinpoint the node.
 

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Forum statistics

Threads
165,936
Messages
2,206,398
Members
79,220
Latest member
Sccrcut8
Back
Top