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Long range load development at 100 yards.

I am a little concerned about your erratic ES. These are 3-shot groups and should be pretty low. The pattern in some is two close, one distant. You might need to do some more load work and locate the charge node before proceeding. [br]
SeatingV1V2V3ES
-0.01​
2882​
2878​
2882​
4​
-0.013​
2898​
2893​
2878​
20​
-0.016​
2895​
2869​
2879​
26​
-0.019​
2870​
2875​
2865​
10​
-0.022​
2890​
2856​
2847​
43​
-0.025​
2867​
2880​
2867​
13​
-0.028​
2858​
2843​
2868​
25​
-0.031​
Error
2866​
2867​
1​
-0.034​
2847​
2848​
2879​
32​
-0.037​
2853​
2848​
2846​
7​
-0.04​
2875​
2854​
2861​
21​
 
Hi Steve,

Thanks for your comments. If you look at my load development on page 67, you can see that the standard deviations where in the teens or single digits and the velocities where higher. Groups size not that good. Do you think it could be a chronometer (shooting chrony) issue or how I am holding the rifle? I really do not like shooting from a bench, I usually shoot prone from a bipod so the bench is awkward for me. The cases where prepped the same, except that in this last test the headspace was set back 0.001 and the test on page 67 it was set back 0.004. Do you think that would make a difference? If you did not have the velocity data which seating depth would you choose?

I have had issues with this chronometer in the past and have sent it back once for repairs.

Thank you for any input you may have it is very much appreciated.
 
I would probably go with .034" jump. My practice is to shoot a 25 shot series, in five 5-shot groups over the chrono, to confirm the choice. I shoot at 30 second spacing and look for consistency between the groups and only a slight rise in velocity as the barrel heats. This simulates match conditions. If it won't perform at the range through 25 shots, it likely will not during a match.
 
Erik Cortina said:
L-46 said:
Another target,
What are your thoughts,
L-46

I don't see a whole lot of hope there. ES are really high, and groups are erratic.
No problem, i will re do the test. Set up my flags and concentrate.
Are you thinking the burn rate is wrong?
The barrel is good, only 300 down the tube
L-46
 
300 RUM said:
so is 100 yard load testing for long range a truly viable product?

It has a methodology and evaluation criteria so at that level alone it is valid. It also offers an approach that will apply for many people - 300 yard plus evaluation approaches are not always possible.

The criteria used to make choices don't require vast amounts of experience to filter and again it is applied at a range where environmentals are more easily managed by the novice or less experienced shooter.

It is a process that is relatively fast to get up and running. The concepts are simple.

To fully benefit it does require a very good and reliable chrony.

It is an approach that is geared towards aggregate.

Ultimately there are holes in targets that prove it works.

I'm sold.
 
300 RUM said:
so is 100 yard load testing for long range a truly viable product?

I've always been able to get my best load only after LOTS of trial and error. That took a lot of time and bullets.
Working on a new 308 Shilen barrel, I tried this method. In two trips to the range I was able to get .262 groups....TWICE.
It's a fast, simple way to get to where you want to be by telling you what the barrel likes. Love it. Thanks Erik !
 
Last year, about four weeks before leaving for Raton and the Nationals and Worlds, I developed a new load for my .300 WSM at 100 yards. Prior to the Nationals, I never shot the load in competition or past 300 yards. I shot with Erik on Team Lapua and we did some pretty decent shooting at times. Any deficiencies that I exhibited there were not due to the load or rifle. The load performed very well, as you would expect when it shot sub-.2" five-shot groups at 100 with ES of 6-9 fps during development. [br]
6BRinNZ makes a good point. An accurate and reliable chronograph is a must as is reasonable confidence in your bench technique.
 
Erik, finally got back to my 22-250 shooting 55 Blitzkings with one consistent charge of 35.9 Varget and Fed210 Gold Medal Match primers. Following your advice, I started the bidding at .005 off (top left, 2.118 comp which is approximately 2.512 OAL), where this was my ONLY 4-shot group of the evening. The rest are all just 3-shot groups. I went from top left to right, moving downward and right, working further and further away from my rifling.

I think I can safely say the 2nd row is out. To me, the 3rd row may hold the most promise in terms of any patterns, where 2.105 comp which is approximately 2.503 OAL or about .018 off... looks to be my best of the evening. Before this thread I might have picked one of the bottom two groups, probably bottom right because I've always heard it is better to have horizontal spread rather than verticle stringing. But this is where I need your expert opinion on where to go from here.

Should I go back to .020 off and re-test my charge (maybe go 35.8, 36.0, 36.1, .3, .5), should I try say .016 - .019 with the same 35.9 again, should I work out beyond .028 off... just continuing the seating depth experimentation with the same consistent 35.9 grain charge - what?

 
pic is really hard to read. Top left was 2.118 comparator (base to ogive), approximately 2.512 OAL at .005 off the lands.
Top right, 2.115 / .008 off. Next row, 2.112/.011 off and 2.108/.015 off. 3rd row, 2.105/.018 off, then 2.102/.021 off with 2.500" as the approximate OAL. This is the group where I thought my first shot, the top one that is circled, may have been at least partially my fault. Finally, bottom row left is 2.098/.025 off followed by 2.095/.028 off at bottom right. If you look at how 2.108/.015 off was coming together from the prior group (2.112/.011) in the second row, then see how POI changes from 2.102/.021 (3rd row right) to 2.098/.025 (bottom left), well... that's what makes me think I may have a sweet spot between say .016 and .019 or even .020 off. The gun is more capable than I am, and well... these are all dead ground-hogs as far as that goes. :D
 
this target was shot off a plastic top bench with a bipod without rubber Feet. it is a 223 with 90 grain bergers out of a 1:6.5 twist 28 .5 inches long barrel.

the question I have is I have many targets to look extremely similar to this this. The load has been worked up in the past and proven to be fairly decent the problem I have is just testing this load for time to time I come up with targets like this with a horizontal string but never a vertical issue.

I'm just curious if there's any others out there who have similar problems retesting a load And getting horizontal stringing
 

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