Long range load development at 100 yards.

[Alex Wheeler]

Heres one for ya, I shot this target a couple months ago. This was shot a 200 yds. I don't really see the groups level out, they climb a little every group. I kind of shot the groups in a weird order, I went left to right then down, then left to right again. I hope you can read the charge weights. Its not on this target but 33.9 flattens out again real nice, but its too hot.

 

[Erik Cortina]

Looks like 33.3 and 33.6 are pretty flat.

 

[Steve Blair]

Heres one for ya, I shot this target a couple months ago. This was shot a 200 yds. I don't really see the groups level out, they climb a little every group. I kind of shot the groups in a weird order, I went left to right then down, then left to right again. I hope you can read the charge weights. Its not on this target but 33.9 flattens out again real nice, but its too hot.

[br]
What were the velocities for the various charge weights?

 

[Erik Cortina]

Here's a copy of the target I made for load development. It has horizontal and vertical lined though the center to help "read" the groups better.

I will also post it on the first post so you guys can find it easier in the future.

 

[tonysnoo]

Well Erik, Thanks for all the advice. here is my attempt at your process. I think I have two nodes, but I want to work around the 43.9. I just wanted to see if you agree or what else you might see. I wish this was a better test. I had a bit of wind to contend with and some of the outer limits of a few groups were definitely me.

 

[Alex Wheeler]

Heres one for ya, I shot this target a couple months ago. This was shot a 200 yds. I don't really see the groups level out, they climb a little every group. I kind of shot the groups in a weird order, I went left to right then down, then left to right again. I hope you can read the charge weights. Its not on this target but 33.9 flattens out again real nice, but its too hot.

[br]
What were the velocities for the various charge weights?

32-2930
32.3 2950
32.6 3040
32.9 3030
33.2 3065
33.5 3070

I have already tested this gun at 1k. 33.9 shot best, but I had ejector marks, 33.5 was ok 5-6'' at 1k. 32.6 is about as good as 33.9.

 

[Erik Cortina]

Well Erik, Thanks for all the advice. here is my attempt at your process. I think I have two nodes, but I want to work around the 43.9. I just wanted to see if you agree or what else you might see. I wish this was a better test. I had a bit of wind to contend with and some of the outer limits of a few groups were definitely me.

I would be tempted to work on 44.3.
But 43.9 also looks good. If you notice, groups on both sides of 44.3 are good and even vertically, I think 44.3 was a fluke, it should have shot better than that.

Your window appears to be from 43.5 - 44.7, so you will have no problem finding a good shooting load with your gun. I would probably just split them and go with 44.1 so that you can be right in the middle of the window.

Wait, after looking at the chronograph numbers, I would be also tempted to go with 43.7, as you only had a 13 fps increase between 43.5 and 43.9

Load 43.7 and adjust seating depth in .003" increments and post results, that thing will hammer!

 

[Joe C]

Erik,

Very good thread my friend. I'm enjoying reading everyone's info. I decided to try your test this week. Went out Tuesday and shot some loads in my .240NMC at 100 yards.

With 3 times fired brass and a 105g Berger BT 35.0 of N150 had the least vertical at .410" with a 5 shot group of .575" ctc.

With fire forming brass 34.8g had a vertical of .160" with a 5 shot group of .255" ctc.

Then on Thursday I went to 600 yards. No surprises.

With now 4 times fired brass the 35.0g load shot a group of 2.760" ctc with a vertical of 2.250" for 9 shots.

With fire forming brass at 34.8g the group was 3.210" ctc with a vertical of 2.295" for 8 shots.

Today I shot a match at ENGC and while I missed a few wind calls and am still working on my technique, the 35.0g N150 load held a consistent vertical of about 2.5" with a wind from the 4 o'clock position at about 10-15 variable.

Thanks again for the help and great info!

 

[Erik Cortina]

Nice job Joe C. Before you know it you will shoot your first clean, and then you will make it a habit. And then one day, in the near future, you will spell my name correctly!

 

[teele1]

Erik, I'd like to ask you to take a look at my latest load test altho at 200 yards. 6CM 115 DTACS with H1000 All loaded at .020 off lands. Loads are left to right 48.7, 49.0, 49.3, 49.6, 49.9. and where should I go from here??? Thank you sir.

 

[Erik Cortina]

Teele1, are the two high shots part of the last two groups?

 

[teele1]

Erik, yes. I was shooting off the reticle and screwed up. Hate to admit it but I did.

 

[Erik Cortina]

teele1, they all look good. Take 49.6 and adjust seating depth. Make sure you post results.

 

[teele1]

Erik, will do. Thank you kindly for the professional input. Kinda tough in Palm Beach County, FL We can only shoot about 1 weekend a month at the Sheriff's Rifle Range Hopefully that will change with the County deeding land to Florida GFC to build a range in 2 years.
jim

 

[teele1]

Erik, so i should start with your recommendation of

"For testing, I start at Jam -.010" and work away from there in .003" increments. "

and work how far out to Jam -.040?? 3 shot groups, correct
Thanks again for the assistance
jim

 

[Erik Cortina]

Erik, so i should start with your recommendation of

"For testing, I start at Jam -.010" and work away from there in .003" increments. "

and work how far out to Jam -.040?? 3 shot groups, correct
Thanks again for the assistance
jim

You can to to jam -.040", but you will find a good load way before that.

 

[tonysnoo]

Well Erik, Thanks for all the advice. here is my attempt at your process. I think I have two nodes, but I want to work around the 43.9. I just wanted to see if you agree or what else you might see. I wish this was a better test. I had a bit of wind to contend with and some of the outer limits of a few groups were definitely me.

I would be tempted to work on 44.3.
But 43.9 also looks good. If you notice, groups on both sides of 44.3 are good and even vertically, I think 44.3 was a fluke, it should have shot better than that.

Your window appears to be from 43.5 - 44.7, so you will have no problem finding a good shooting load with your gun. I would probably just split them and go with 44.1 so that you can be right in the middle of the window.

Wait, after looking at the chronograph numbers, I would be also tempted to go with 43.7, as you only had a 13 fps increase between 43.5 and 43.9

Load 43.7 and adjust seating depth in .003" increments and post results, that thing will hammer!

Erik, as such a newbie to this sport, I sure appreciate your feedback. More questions (of course): Will these nodes hold consistent with other 105s using the same powder? I assume even if they did, the seating depth would be quite different?

As I studied my chrony data and the targets, I'm going to definely test further with 43.7. I also am curious about 44.5 since I only had 15fps between 44.3 and 44.7.....thoughts?

Thanks,
Tony

 

[Erik Cortina]

You have to start over with a different bullet.

Give 44.5 a try as well.

 

[tonysnoo]

I picked a dumb day to do my first seating test. I thought I was going to have a quiet day at our spot. After I got all set up the wind came out of no where to put some big question marks in the results. Even though I couldn't hold still, I think I still got some worthwhile data. Here is my tests with the 43.7 node.

 

[Erik Cortina]

Looks like the came together pretty good. But if it was that windy, you may have to do it again to see results more clearly.

Were you adjusting seating depth in .003" increments?