Load Development

[Dub]

This was 10 shots at 100 yards when I was chronographing from 71.2-73.0 grains when I was first starting load development. It wants to shoot. I just don’t why now I’m having 30-40fps change in velocity when everything has been the same throughout my process.

this looks pretty good to me

 

[Bindi2]

Jud the next time you do your workup I would encourage you to shoot a target with the same shots, and see what it tells you. As I mentioned earlier I do not have any confidence relying on this chrono method, particularly because I cannot see any reason why it would reflect the harmonic vibration behavior of the barrel which leads to minimizing the effect of velocity variation on vertical.

The tuner does the harmonics.

 

[INTJ]

The only thing that I question with shooting groups with each powder charge is what if your seating depth isn’t tuned. Or do you just pick what powder charge shoots the best, even if none of them are exceptional? Or do you pick the groups that shoot to the closest POI of each other like OCW?

I missed this one. I start by picking a seating depth and the running 5-shot groups through the range of powder loads. I pick the best powder load and then run searing depth. Then I go back and tweak the powder load at the best seating depth.

For a match I will pick seating depths on either side of the best one and check that on tuning day. I may recheck the best, then I load up my rounds, draw second relay and/or have bad conditions and then none of that mattered........

 

[Jud96]

Well I went back to the range and shot 70.0gr just to see. It went 2922 with an ES of 20. This isn’t great, but it backs up my findings from earlier. This is 42fps faster than my previous testing, and the 70.4gr load was also 42fps faster than my previous findings. When I tested 71.4 it averaged 2978, which is 30fps faster than my previous tesing. I’ll have to double check my round count, but this is around 40-50 shots since I cleaned my barrel. I’m not sure if my barrel just takes 20-30 shots to settle down after cleaning or what. Maybe the brass took 2 firings to completely form? I’m not sure but it’s definitely about 40fps faster now.

 

[Jud96]

I made some progress today and I’m happy with my results. I dropped my load down to 69.7gr and kept everything else the same. I felt I was getting close to a node because my ES continued to lower as I dropped the charge weight. This load went 2909fps with an ES of 16. This is acceptable and it shot a very good group. I believe this brass may have taken a couple firings before fully forming, or this barrel needs 20 shots or so to foul in and level out.

 

[INTJ]

Hopefully it will repeat and you are tuned

 

[JOSHUA EARLE]

My guess would be one of two things. Either inconsistent ignition or fouling. As you build up fouling i a new barrel you generally see an increase in velocity. When you clean the bore, if you are removing all of the copper fouling you will continue to chase this around. I personally do not clean copper out of the bore unless it really is necessary.

What primer are you using?

I use Reloder 26 quite a lot. I have found best results with CCI 250 primers in my 300 win mag. I get about 3030 fps with a 200 grain eldx with 1 inch 5 round groups.

My advice, don't clean the copper from the bore

 

[Jud96]

My guess would be one of two things. Either inconsistent ignition or fouling. As you build up fouling i a new barrel you generally see an increase in velocity. When you clean the bore, if you are removing all of the copper fouling you will continue to chase this around. I personally do not clean copper out of the bore unless it really is necessary.

What primer are you using?

I use Reloder 26 quite a lot. I have found best results with CCI 250 primers in my 300 win mag. I get about 3030 fps with a 200 grain eldx with 1 inch 5 round groups.

My advice, don't clean the copper from the bore

I’m using Federal 215s. I’ve never had a problem with these primers before. I did completely clean the barrel of copper and carbon before doing load development. I’m assuming that’s where my inconsistencies were coming from. It’s now producing repeatability and predictable velocities. Next time I clean I’m just going to clean the carbon out and not clean it to bare metal.