Thread: Testing a conventional approach to load development

Originally Posted by c-dog

Just done a quick load development in a howa mini and was quite happy with the results, had to break up the groups as the mirage was a bit of an issue.

Checked length to refiling and dropped back 2mm to suit ease of mag feeding.

Started .5 grain above minimum and .5 grain increase until 25.5gr. 26gr was max in the adi for 69gr sierra hpbt and I am using 69gr targex. Loaded 12 rounds at 25.5 worked up looking for pressure, one over the chronograph and the last 10 into a group (would have liked to put them all over the chronograph but it was in use) mirage became an issue at about 4 rounds so had to space the shots out. I also used this range session to mount a scope (used some sako factory ammo for sight in)

I don't have the app used above but looks about 19mm outer edge to outer edge at 50mm high at 100m.

Going to load up 30 or so to put in the safe ready to go hunting then have a play with the other new brass and see if I cam get the 80gr eldm to work. In the same rifle (although i think it will be too compressed to work in the mag)

Attachment 273557

That's a good shooting Howa. Is it in a factory stock? @c-dog

Originally Posted by gimp

That's a good shooting Howa. Is it in a factory stock? @c-dog

It's a Ken Henderson stock. I think it may have been @Dreamer old rifle which I purchased off @25/08 IMP
Only taken out hunting for wallaby with factory ammo (sako stuff seems to shoot pretty good) but thinking I'll take it out looking for a deer now.
How long are your 80gr eldm seated out, I can go to about 62.5mm so will see what sort of velocity and accuracy I can get with the magazine limitation.

I'm at about 61mm OAL for the 80ELDM, my throat is shorter than I really thought. Next barrel I will get it throated a little longer

Originally Posted by gimp

I'm at about 61mm OAL for the 80ELDM, my throat is shorter than I really thought. Next barrel I will get it throated a little longer

Ok, I thought it was going to be too far in the case, I've settled at 62mm so I'll see how it goes, from the research I've done it looks like the howa minis seem to stabilize them ok. I'll report back this evening.

Testing done for the arvo about 56mm outside diamater 10 shot group with the 24gr charge. Looks like I will stick with the targex at this point, half tempted to get a box of 77smk. I've got 20x 80gr targex here that I can also do a test with. Apart from the different projectiles and powder all was the same rest brass etc (new brass checked to fit chamber and measure for trim length, give a visual then load) I had high hopes for the 80gr eldm as I have had good results in other calibers but doesn't look like it's ment to be in this rifle, (I may try again with 2206h) I've never done loads in this sequence before but it's fairly quick and to the point (3 shot groups could have had me fooled into thinking it was 1/2 moa load) ill try get better data with my next lot of testing (the lane with the chronograph setup is usually a bit busy)

Originally Posted by c-dog

Testing done for the arvo about 56mm outside diamater 10 shot group with the 24gr charge. Looks like I will stick with the targex at this point, half tempted to get a box of 77smk. I've got 20x 80gr targex here that I can also do a test with. Apart from the different projectiles and powder all was the same rest brass etc (new brass checked to fit chamber and measure for trim length, give a visual then load) I had high hopes for the 80gr eldm as I have had good results in other calibers but doesn't look like it's ment to be in this rifle, (I may try again with 2206h) I've never done loads in this sequence before but it's fairly quick and to the point (3 shot groups could have had me fooled into thinking it was 1/2 moa load) ill try get better data with my next lot of testing (the lane with the chronograph setup is usually a bit busy)
Attachment 273753

The 80s the big group under the handloaders logo? My mini seems to hate the eld range with all 3 barrels.

Originally Posted by Stocky

The 80s the big group under the handloaders logo? My mini seems to hate the eld range with all 3 barrels.

Yea mate correct, I should have said. What are you running in yours? I've got a few 69gr targex if you want to try some of those. That's the group to the right, pretty happy with them.
Also did 3 shots without the suppressor and the were same height but 70mm to the left, more for my reference than anything. Are your three all 223? I like the look of the 6mm arc barreled action but then I'd have to muck around and fine another stock dies etc

Originally Posted by c-dog

Yea mate correct, I should have said. What are you running in yours? I've got a few 69gr targex if you want to try some of those. That's the group to the right, pretty happy with them.
Also did 3 shots without the suppressor and the were same height but 70mm to the left, more for my reference than anything. Are your three all 223? I like the look of the 6mm arc barreled action but then I'd have to muck around and fine another stock dies etc.

2 howa barrels and and an aftermarket nz barrel I wont name yet all in 223.

Originally Posted by c-dog

Just done a quick load development in a howa mini and was quite happy with the results, had to break up the groups as the mirage was a bit of an issue.

Checked length to refiling and dropped back 2mm to suit ease of mag feeding.

Started .5 grain above minimum and .5 grain increase until 25.5gr. 26gr was max in the adi for 69gr sierra hpbt and I am using 69gr targex. Loaded 12 rounds at 25.5 worked up looking for pressure, one over the chronograph and the last 10 into a group (would have liked to put them all over the chronograph but it was in use) mirage became an issue at about 4 rounds so had to space the shots out. I also used this range session to mount a scope (used some sako factory ammo for sight in)

I don't have the app used above but looks about 19mm outer edge to outer edge at 50mm high at 100m.

Going to load up 30 or so to put in the safe ready to go hunting then have a play with the other new brass and see if I cam get the 80gr eldm to work. In the same rifle (although i think it will be too compressed to work in the mag)

Attachment 273557

The 69 targex always shot well and I think that was the magic load.
I can't remember if I tried 80grn Targex or not but they should shoot ok.
I never had any luck with the 80 ELDM in either of my rifles with 1-8 twist barrels.

Sent from my CPH2531 using Tapatalk

Originally Posted by gimp

So conclusion - with this rifle, bullet, brass, powder and shooter combination it is not possible to identify any difference in precision between loads with different seating depths by testing with 3 shot groups, at .003 inch increments of seating depth (as recommended by Erik Cortina, if he isn't the person to listen to for this then who is ?). Or 20rd groups of same.

First off I’d like to say this is super interesting and “ good on ya “ for going to the effort to both conduct these tests and to document them so thoroughly

I’m doing some load development at the moment for my 6.5CM with Sierra 130gr TMK projectiles.

So my initial test is always for Powder charge weight ( using 2209 powder ) with the projectile approximately 45 thou off the lands . I use the word approximately because I have yet to use / find a method that is spot on accurate when measuring throat length .
Starting at 1.0 gr below Sierra’s listed max charge I loaded up 6 rounds of each powder charge going up in 0.5gr increments ending up 0.5gr over their recommended max .
I shot those rounds and experienced zero pressure signs , all shot acceptable groups ( below 25mm at 100 yrds ) with an apparent improvement as the charge weight increased . All of this means “ Diddly Squat “ in the grand scheme of things but I wanted to find my upper limit of safe powder charge .
Now I have just loaded up another batch of loads using my chosen powder charge but with a selection of different seating depths. I make 10 thou increases in CBTO length.
So now in theory I am going to test 45 thou / 35 thou / 25 thou / 15 thou jump to see if things tighten or loosen as the seating depth changes.
I can’t understand why anyone would F*#k around with 3 thou changes , maybe in the world of Benchrest / F Class , but not in the world of Hunting / Factory barrels.
This seating depth test is just to see if there is an obvious trend developing either good or bad and then and only then will I load a decent amount of the chosen brew and shoot multiple 10 shot groups .

Originally Posted by Ground Control

First off I’d like to say this is super interesting and “ good on ya “ for going to the effort to both conduct these tests and to document them so thoroughly

I’m doing some load development at the moment for my 6.5CM with Sierra 130gr TMK projectiles.

So my initial test is always for Powder charge weight ( using 2209 powder ) with the projectile approximately 45 thou off the lands . I use the word approximately because I have yet to use / find a method that is spot on accurate when measuring throat length .
Starting at 1.0 gr below Sierra’s listed max charge I loaded up 6 rounds of each powder charge going up in 0.5gr increments ending up 0.5gr over their recommended max .
I shot those rounds and experienced zero pressure signs , all shot acceptable groups ( below 25mm at 100 yrds ) with an apparent improvement as the charge weight increased . All of this means “ Diddly Squat “ in the grand scheme of things but I wanted to find my upper limit of safe powder charge .
Now I have just loaded up another batch of loads using my chosen powder charge but with a selection of different seating depths. I make 10 thou increases in CBTO length.
So now in theory I am going to test 45 thou / 35 thou / 25 thou / 15 thou jump to see if things tighten or loosen as the seating depth changes.
I can’t understand why anyone would F*#k around with 3 thou changes , maybe in the world of Benchrest / F Class , but not in the world of Hunting / Factory barrels.
This seating depth test is just to see if there is an obvious trend developing either good or bad and then and only then will I load a decent amount of the chosen brew and shoot multiple 10 shot groups .

Note I've tested larger jump increments as well, with a secant ogive bullet (following Berger method) - 0.040" steps. With that bullet, I have largely only fired 3 shot groups however none of the shots fall outside of what can be expected from the single 10 shot group I shot - happy to re-test any of them with a larger sample size but there's no indication that any of them are any different.

https://www.nzhuntingandshooting.co....ectile-113861/



I'd be really interested to see your results, if you were able to test the depth that you conclude is the worst- as well as the best - and see if there's any real difference that can be resolved

Well I shot those seating depth test rounds and the conclusion is ………

I need to get better at my shooting form and trigger skills
All shot very well ( 17mm / 15mm /18mm ) at 100 yrds with no outstanding best or worst when you take into account my shooting ability and low number of rounds ( 2 x 3 shot groups for each load , those measurements are an average of the two groups )
I’ve come to the conclusion lately that if your Rifle likes the bullet / powder combo it doesn’t matter much about the other stuff .
I’m just going to load up 50 rounds ( of the 15mm load , not because I strongly feel it’s better , but hey why not ) and zero the Rifle with 3 x 10 shot groups and go kill stuff with the other 20 .
I don’t shoot at distances greater than 300 yrds with this Rifle and trying to achieve a genuine 0.5 moa gun is a waste of time when with minimal development I’m confident that 10 round groups will be hovering around the 1 moa + or - a fraction with any of the combo’s tried already

Originally Posted by Ground Control

Well I shot those seating depth test rounds and the conclusion is ………

I need to get better at my shooting form and trigger skills
All shot very well ( 17mm / 15mm /18mm ) at 100 yrds with no outstanding best or worst when you take into account my shooting ability and low number of rounds ( 2 x 3 shot groups for each load , those measurements are an average of the two groups )
I’ve come to the conclusion lately that if your Rifle likes the bullet / powder combo it doesn’t matter much about the other stuff .
I’m just going to load up 50 rounds ( of the 15mm load , not because I strongly feel it’s better , but hey why not ) and zero the Rifle with 3 x 10 shot groups and go kill stuff with the other 20 .
I don’t shoot at distances greater than 300 yrds with this Rifle and trying to achieve a genuine 0.5 moa gun is a waste of time when with minimal development I’m confident that 10 round groups will be hovering around the 1 moa + or - a fraction with any of the combo’s tried already

Thanks for reporting back. Can you post the targets?

I don't think it's terribly surprising - even if one is a believer in seating depth changing precision, the TMK is a tangent ogive bullet and not believed to be sensitive.

I've posted before that the order of effect size when changing variables, in my view, is something like this (gaps indicative of relative importance) :

Barrel quality (get a good barrel, properly chambered)



Bullet quality

Powder choice and how it interacts with specific bullet and barrel
Brass quality











--------unproven to be an effect-------------------
Any tuning of powder charge or seating depth






I'm not sure I believe there is such a thing as a genuine 0.5MOA rifle - using the definition of precision that refers to the full dispersion of the true cone of fire. I have yet to see any evidence that such a thing exists. Certainly in practical terms, the effect size of shooter error swamps rifle precision in the noise and no-one could actually take advantage of it in a hunting scenario

So given all that. Are we not back too looking for a rifle that constantly groups 3 or 5 shots together close too our desired POI?

A ammunition manufacturers dream.All this shooting science to waste ammunition on.Enjoy it guys,lols.