Long range load development at 100 yards.

[Michaël T]

My turn!

6.5 x 47 Lapua
31" Krieger 4 groove
N550 Powder
Wolf small rifle magnum primers
Lapua 136 gr. Scenar L

Powder test from 38.0 gr. to 42.0 grains VV N550. What do you guys think?

i think 38.5
speed is there and groups left and right look good, seating depth is next,
Erik where are you?

 

[Erik Cortina]

Well, I picked 40.2 gr. groups were very close vertically and with good ES. When I shot this test, I was getting some hang fires with the Wolf primers. When I tested seating depth, I was able to tighten the groups at .-016" but was still having hang fires so I had to change primers and start again.

I will post pictures of the seating depth test later.

 

[troutslayer]

40.5 with regards to Erik's. ***i posted this before Erik's post but it shows after his post? I think my time and 6mm's time are off a bit?

 

[lawrence97]

Did testing at 100 yards with H4831SC to try out .003 neck clearance. I posted results in a previous thread using .004-.005 neck clearance. ES is a little tighter now but I am still not happy. My previous data pointed towards 54.8g with 180's seated with a .012 jump. With current testing I maintained .012 jump. Temps. ranged from 65-72 with a slight breeze towards the end of testing as well as moderate mirage.

What charge should I focus on or what looks promising?

Thanks for your comments.

 

[lawrence97]

Tested from 54.8 to 55.4 in smaller increments with .012 jump. Happy with groups but I have not been able to reduce my ES. I am weighing to the kernel and doing the best I can for brass prep. The only thing I have not tested is a primer other than Fed210.

Comments welcome.

 

[Erik Cortina]

What was the ES at 55.4?

 

[lawrence97]

Oops, forgot to write it in....


3@55.4
Series 7 Shots: 3
Min 2903 Max 2937
Avg 2920 S-D 17
ES 34

Series Shot Speed
7 1 2937 ft/sec
7 2 2903 ft/sec
7 3 2920 ft/sec

 

[Erik Cortina]

Load 55.2 and use it as a fireforming load. Once you have all brass fire formed, test again. ES should come down with fire formed brass.

 

[lawrence97]

Will do. 10 more pieces left to form. After prepping I will run the same charges again.

Thanks.

 

[Keith Glasscock]

There is something about the velocities bothering me. What chrono are you using?

Is the light changing on you (like a cloud flickering through the sun or clouds getting grayer and lighter?

 

[lawrence97]

I am using a magneto speed. It is not affected by light. The only thing I can think of is that I was using virgin brass which is why I will retest with once fired brass.

 

[Keith Glasscock]

Same here on the magnetospeed. Gave up on light sensing chronos.

On your first set of targets, upper middle and lower right both show 55.1 for charge, but a 20 fps difference in avg velocity. Seems odd to me. I'm watching your development closely as my 284 with same bbl length and components is almost done.

What freebore are you running, and what is you oal? Just curious.

Thanks, Keith

 

[lawrence97]

On the post with two target pics I had about a 45 min delay in between each set of targets and the temps increased by a few degrees. I had to go home, load some more and head back out. The barrel cooled down a little when I got back out and 54.8 and 55.1 was used to warm up! Also, the higher velocity on the last 55.1 group would be due to slight temp increase and barrel fouling. 55.1 has always been in the 2905 fps range plus or minus a few due to temps and fouling.

I am running a .207 freebore. I do not have an oal but using MY tooling, MY round measures 2.495 from base to ogive and that is a .012 jump from MY baseline. I emphasize on MY because your measuring tools could be different as well as your bullet lot, brass lot and baseline measurement. You will most likely need to start from scratch for your rifle. I am still happy to share any of my findings and try to be as detailed as I can.

I really like the magneto because the range I regularly go to is not the best terrain or conditions to be setting up sky screens and any other items. It used to take me about 15-20 mins to setup a CED millenium and now I am up and running in less than 5.

 

[Keith Glasscock]

Thanks, I'm going to run the .218 freebore reamer from ptg. I am using your info to get a starting point for QL. Your velocity vs charge lines up well with another shooter I know well (he's running 55.4). As always, QL predicts a much higher charge to get those velocities (that's why I'm going to start at 53).

 

[savageshooter86]

Erik what are you thoughts? Top left is 45.7. Looking to pick a charge and do seating test

 

[lawrence97]

Finally got some different primers to test instead of the federal 210's. I tested my usual start load of 54.8 with intentions of going up to 55.4.....but with these primers my velocities were significantly higher and I had to stop at 55.2 due to hard bolt lift and no desire to toss my brass after one load!

Last 5 groups were toned down and go from 53.3 to 54.5. By the time I went back home and loaded for the last 15 rds. wind had picked up and mirage was messing with my eyes. The brass is once fired and I am glad to see that my ES has also dropped.

Erik, any suggestions?

 

[Erik Cortina]

55.0 and 55.2 look really good. I would split the difference and go with 55.1 to give you some room for error.

 

[Erik Cortina]

Erik what are you thoughts? Top left is 45.7. Looking to pick a charge and do seating test

I'm sorry, but I don't see anything worth persuing here.

 

[lawrence97]

Erik, with the Russian primers and loads above 54.8 I am getting good groups but I get a hard bolt lift and very faint ejector marks. I do like the results but I'm sure my primer pockets will be loose after getting those velocities. Is it normal to see 15-30fps change in velocities with just a change in primers?

 

[Erik Cortina]

Primers can as you can see increase speed.

Back down in your charge and look for lower node, it should not be hard to find.