LR Load development... I'm going to start a dumpster fire

[quest450]

Thanks Brett, I'm gonna try it in my BRA, I have a new barrel I need to break in and I know the seating depth and powder charge they usually like.

 

[Bc'z]

Thanks Brett, I'm gonna try it in my BRA, I have a new barrel I need to break in and I know the seating depth and powder charge they usually like.

I was testing Bart's 105's and VT 103's
Side by side getting ready for Freedom west coast national last year when I shot that seating test, I didn't finish load development with the 105's but will pick it back up once barreled action comes back from Zack.
FWIW... The Vapor Trails with N540 clocked in at 2880 all said and done.
Good enough for 6 cleans with a 80% X count earning me a 1st, three 2nd, and two 3rd place finishes at our local club matches.
I used to shoot middle of the pack in our club, now I'm shooting at the top.

 

[Turbulent Turtle]

Here is what I did to start this season in 1K BR at Deep Creek with my 300 SAUM IMP Heavy Gun.

First, I pulled a Krieger 1.45 straight barrel that had 470ish rounds and threw it away because I couldn't get it to shoot last year. Then I chambered 1.45 straight Bartlein than @tom let me buy from @Alex Wheeler.

I did some initial testing at 300 yds that was almost useless. For 300 yds I shoot 5-shot groups. I thought I identified a couple nodes, one at 60.5 grains (that I thought would work best) and one at 62.5. Based on the 300 yd nodes, I loaded up three tests for 1000 yds at the range the day proper to the match. They were:

#1: 58.4, 58.7, 59.0, 59.3
#2: 60.2, 60.4, 60.6, 60.8
#3: 62.0, 62.4, 62.6, 62.8

I have shot this cartridge quite a bit. I know that it likes sorted Berger 200 Hybrids jammed around .021 with my current reamer--that I also got from Alex. Based on the 300 yd test, I thought the #2 1000 yd test would be best. It was the worst. The second best was the #3 test, but it was tad hot.

The #1 test shot the best at 1000 yds. This test was almost an afterthought. I know nodes are typically 2.5 to 3% of the powder charge, so I loaded groups to cover that range--that's why these were in .3 grain increments instead of .2.

Here is what the #1 test looked like:

View attachment 1646532

If I had been able to shoot one more ladder on Friday it would have been 59.0, 59.2, 59.4, 59.6. I really need to see what happens at a little above 59.3. I will do that next match. Please note these are shot round robin, all at the same POI, in a 12 shot string with colored bullet tips.

I shot 62.4 and 59.3 for my groups on Saturday to see which would shoot best. I shot 62.4 first and it was a little over a 6" 10-shot group. 59.3 gave me a 3.95" 10-shot group and I won heavy gun group agg that day. I shot a pair of 5s on Sunday with that load and wound up 4th in group agg.

I think I can tune it a little better, but I don't think I can match Tom's Sunday HG groups from his 300 WSM of 3.5 and 3.3. That was AMAZING!!

I think I saw those hieroglyphs on the crashed ship at Roswell. Isn't that the location of the Engineers' star?

 

[ORjeff]

So Aaron, it seems like you're hoping someone offers up something different. Here you go....
First, my approach is not for everyone and I'm not claiming it's any better. My approach is highly influenced by my history as an engineer with HP characterizing inkjet printers (shooting 100s of drops out of thousands of nozzles and measuring accuracy of drop placement). I recall you once mentioning that you're a EE or something that makes me think you have a technical background so I'm guessing you know how to use a spreadsheet. So here's how I do it.....

I don't measure groups. I measure MV and POI vs POA for every shot: horizontal (X) and vertical (Y) distance from center of bullet hole to center to aim point. I print out my own grid with my home printer but the easiest way to do this is to just use commercial graph paper. I like using 8-1/2x11 targets because then I can put them all into a three ring binder and keep everything organized. I use one POA for one shot, my target has 5 POA's so I get one "group" of five per sheet. The range I shoot at has backer plates that I attach these to with a staple gun, I can usually put up 12 sheets which is about all I ever have time for anyway (60 shots) in one session.

So, after I'm done I gather up the targets and record the X and Y values into a spread sheet along with whatever else matters like powder charge, MV, and bullet seating depth (which I measure differently than everyone else but that's a long story). Then I start making lots of calculations using the spread sheet functions. I calculate average X and Y displacement for each page to get the center of the "group". Then I calculate the distance each shot was from that center. I also calculate MaxX-MinX and MaxY-MinY then mulitply those to get an area value (not the same as the group size but close). I also look at MV, ES, and MV_avg, etc, along with whatever else I think matters. (I don't use SD by the way, but's that's another long conversation). I'm a visual learner/thinker so once I get all those numbers calculated I start making charts (I use scatter plots, btw). I look at X variation by itself and then Y variation, then "group size" variation. Then I look for correlations between those and MV and jump or whatever it is that I'm testing. The results are often typical and reasonable but something curious usually shows up (minimum group size when ES was at it's maximum was part of my last test result). Hopefully I end up with data that I can make a decision on and move forward to the next step.

 

[tom]

I work at it at the distance I plan to shoot and just shoot a ladder. It will tell you what to do.



Tom

 

[Evan]

I work at it at the distance I plan to shoot and just shoot a ladder. It will tell you what to do.

View attachment 1647040

Tom

Just for those of us who may be a little thick, I interpret that target as 60.3-60.5 is the area to explore again (maybe 60.2 up to 60.6 in 0.1gn increments) because it slowed down how quickly it was climbing the target through that range, and while I don't like the shift to the left, that could be wind. Is that a fair reading?

 

[jelenko]

I work at it at the distance I plan to shoot and just shoot a ladder. It will tell you what to do.

View attachment 1647040

Tom

That's incredible shooting! Was there any wind?

 

[ELR LVR]

I work at it at the distance I plan to shoot and just shoot a ladder. It will tell you what to do

View attachment 1647040

Tom

and this my friends, is why I'm still practicing
His 1000 yd groups look like my 600 yd groups

 

[Scott H]

This is what I use for the standard ladder method. I make these graph charts with 1/4 inch line spacing and layout your charge weights for the range of powder charge. I will shoot this two times, low to high, so the charts will show the waves changing as barrel temps change some also. I will do the same thing for seating depth. It's very easy to see the waves smooth out when you hit a node.

 

[jelenko]

and this my friends, is why I'm still practicing
His 1000 yd groups look like my 600 yd groups

Yeah. I shoot prone with a sling - the upper two groups would be great at 200 yards.

 

[ELR LVR]

Yeah. I shoot prone with a sling - the upper two groups would be great at 200 yards.

Definitely agree, that discipline is almost a lost artform

 

[tom]

Just for those of us who may be a little thick, I interpret that target as 60.3-60.5 is the area to explore again (maybe 60.2 up to 60.6 in 0.1gn increments) because it slowed down how quickly it was climbing the target through that range, and while I don't like the shift to the left, that could be wind. Is that a fair reading?

I have the date wrong, as that was Friday of the match weekend. Ya, I picked out 60.5 and will shoot a less coarse ladder next match. I didn't plan to shoot this bullet, and was relay 3 of my (f-around) testing Friday morning. I do recall saying to Glenn if that wasn't a "test" I would have leaned over a bit on our drive down to look.

Tom

 

[ricco1949]

This is what I use for the standard ladder method. I make these graph charts with 1/4 inch line spacing and layout your charge weights for the range of powder charge. I will shoot this two times, low to high, so the charts will show the waves changing as barrel temps change some also. I will do the same thing for seating depth. It's very easy to see the waves smooth out when you hit a node.

Also, very obvious to see the increased charges taking out the vertical.

Did you get pressured out at 51.4? Woulda been interesting to see what woulda happened at 51.6 and beyond.

It's relatively level all the way across with little indication of a sin wave....unless the early vertical is trying to show that.

 

[old_heli_logger]

So Aaron, it seems like you're hoping someone offers up something different. Here you go....
First, my approach is not for everyone and I'm not claiming it's any better. My approach is highly influenced by my history as an engineer with HP characterizing inkjet printers (shooting 100s of drops out of thousands of nozzles and measuring accuracy of drop placement). I recall you once mentioning that you're a EE or something that makes me think you have a technical background so I'm guessing you know how to use a spreadsheet. So here's how I do it.....

I don't measure groups. I measure MV and POI vs POA for every shot: horizontal (X) and vertical (Y) distance from center of bullet hole to center to aim point. I print out my own grid with my home printer but the easiest way to do this is to just use commercial graph paper. I like using 8-1/2x11 targets because then I can put them all into a three ring binder and keep everything organized. I use one POA for one shot, my target has 5 POA's so I get one "group" of five per sheet. The range I shoot at has backer plates that I attach these to with a staple gun, I can usually put up 12 sheets which is about all I ever have time for anyway (60 shots) in one session.

So, after I'm done I gather up the targets and record the X and Y values into a spread sheet along with whatever else matters like powder charge, MV, and bullet seating depth (which I measure differently than everyone else but that's a long story). Then I start making lots of calculations using the spread sheet functions. I calculate average X and Y displacement for each page to get the center of the "group". Then I calculate the distance each shot was from that center. I also calculate MaxX-MinX and MaxY-MinY then mulitply those to get an area value (not the same as the group size but close). I also look at MV, ES, and MV_avg, etc, along with whatever else I think matters. (I don't use SD by the way, but's that's another long conversation). I'm a visual learner/thinker so once I get all those numbers calculated I start making charts (I use scatter plots, btw). I look at X variation by itself and then Y variation, then "group size" variation. Then I look for correlations between those and MV and jump or whatever it is that I'm testing. The results are often typical and reasonable but something curious usually shows up (minimum group size when ES was at it's maximum was part of my last test result). Hopefully I end up with data that I can make a decision on and move forward to the next step.

Howdy Jeff,
Did you go to LBCC? Me too, I graduated in 1995...I ended up at Intel for 21 years. I may have designed some of the stuff in your hands right now...the last technology I finished was USB type-C
Good luck and good shooting everyone!
Steve

 

[Scott H]

Also, very obvious to see the increased charges taking out the vertical.

Did you get pressured out at 51.4? Woulda been interesting to see what woulda happened at 51.6 and beyond.

It's relatively level all the way across with little indication of a sin wave....unless the early vertical is trying to show that.

View attachment 1647092

Yes, 51.4 started getting a little sticky bolt lift. This was shot at 100 yards. I will usually run them at 200. The 50.6 is what i used for the sighters and slight barrel warming. Do the same test out at 500 plus and stack the charts to see how the same load changes further out. Make one chart and run it through the copier.

 

[Nvcnvc]

I'd start with seating, then tune powder.
Try it, you can thank me later

^ This...

Seating depth affects barrel oscillations more than any other change (primer, amount of powder, neck tension, etc). I use a lower charge and do seating depth first. Then I go up in charge and look for pressure signs, velocity plateaus, or small groups. I do my seating depth at 100 yds, and group testing at 600 yds (the longest available distance at my LGC). Then, You can play with a tuner if you have one.

 

[Fast14riot]

^ This...

Seating depth affects barrel oscillations more than any other change (primer, amount of powder, neck tension, etc). I use a lower charge and do seating depth first. Then I go up in charge and look for pressure signs, velocity plateaus, or small groups. I do my seating depth at 100 yds, and group testing at 600 yds (the longest available distance at my LGC). Then, You can play with a tuner if you have one.

This.

I own my reamer, I know what it likes and where it shoots as far as seating depth, but I'll still do a depth test first across a small range around where it's known to shoot. Mainly for lot to lot checks. Then I'll do a sweep across maybe 1 grain for charge weight. The really nice thing is, I fire form my brass in the old barrel for the new one, since I shoot an AI chambering and it'll be within .001" of headspace after two firings in the old barrel.

Once a 100y zero is obtained, I go straight to 300, then either 600 or 1000 club match, depending on the schedule. Shoot 3, 20 round tests and settle on something for the next match.

 

[zap]

I was testing Bart's 105's and VT 103's
Side by side getting ready for Freedom west coast national last year when I shot that seating test, I didn't finish load development with the 105's but will pick it back up once barreled action comes back from Zack.
FWIW... The Vapor Trails with N540 clocked in at 2880 all said and done.
Good enough for 6 cleans with a 80% X count earning me a 1st, three 2nd, and two 3rd place finishes at our local club matches.
I used to shoot middle of the pack in our club, now I'm shooting at the top.

Bz’s,
What exactly will you then load up to shoot at at 300 yards with the colored markers, as far as load?
Are you loading 3 shot groups of a certain charge?
This is a very interesting thread. Thank you all !

 

[Bc'z]

Bz’s,
What exactly will you then load up to shoot at at 300 yards with the colored markers, as far as load?
Are you loading 3 shot groups of a certain charge?
This is a very interesting thread. Thank you all !

After seating I load a 3 shot charge ladder, usually in .3 grain increments up to, but not always to published max charge.

 

[zap]

Gotcha, thanks!