"Hybrid" load development test results - any ideas?

[tstanek]

Hi guys,
I did kinda hybrid load dev. testing today. Shot 4 shot groups over the Magnetospeed and measured all the speeds. Could you check the results and maybe put some insight to that, especially if sth particular could be taken from it? All the details are on the pics.
Thanks a lot for any hlp!
Cheers
T.

 

[straightshooter1]

Hi guys,
I did kinda hybrid load dev. testing today. Shot 4 shot groups over the Magnetospeed and measured all the speeds. Could you check the results and maybe put some insight to that, especially if sth particular could be taken from it? All the details are on the pics.
Thanks a lot for any hlp!
Cheers
T.

Time to run that same test one more time to see if that data correlates. If it were me, I'd load up those loads from 23.3 through 23.6 (even to 23.8) without the MagnetoSpeed. I like the 23.6 numbers and the group, but need confirmation shots.

 

[b6graham]

shot a few more 5 shot groups with 23.6 and maybe 23.8

that's about the speed i'd think you want for a 69gr 18" AR

assuming the magnetospeed is mounted on the rail leave it on. if its mounted on the barrel id def only be shooting groups without it and get speed data seperate

 

[OREGUN]

in “endless supply of components” world, I’d say load a bunch at 23.6 and a bunch at 23 and see what a few more groups look like. Also, load up to 23.8 and check that too. But, since this is “no components available” world, I’d load 23.6 and try a few different seating depths to see which has the best group/to make sure it’s not super seating depth sensitive, and be done.

Either way, you want to stay away from 23.2 as any increase toward the velocities of 23.4 seems like a bad thing. I’d want to know what happens if 23.6 speeds up a bit which is why ide check 23.8….protects you from shit groups as the barrel speeds up and over pressure if the temps go way up/it rains.

The house trolls will be along at any moment to tell you your process is shit. Forewarned is fore-armed.

 

[Feniks Technologies]

Purely based on chrono numbers and sample sizes here is your SD and a 95% confidence interval in parentheses:

22.4: 5.8 (3-22)

22.6: 9.9 (7-37)

22.8: 21.7 (not worth calculating)

23.0: 25.9 (not worth calculating)

23.2: 16.3 (not worth calculating)

23.4: 16.4 (not worth calculating)

23.6: 6.2 (4-23)


The numbers in parentheses is the range your SD is 95% likely to fall into over the long haul.

So, if you plan to shoot at a distance where velocity is going to matter, then only three of those charge weights are worth pursuing at this point.

That’s if you want to give yourself the best chance *based on the data you provided here*.

 

[Feniks Technologies]

I would work around 22.5 and work with seating depth.

And/or I would load 23.8 and see if it performs similar to 23.6. If so, I’d work in 23.7 and work on seating depth.

 

[tstanek]

Thanks a lot to all of you guys! Really valuable inputs for me I explained myseIf badly, didn’t mean by this “hybrid” load dev. that i was trying to discover some new method or so. Just wasn’t sure about the stuff you have answered so far and also how to correlate those speeds with group / if there’s even sense of doing that.

 

[OREGUN]

Purely based on chrono numbers and sample sizes here is your SD and a 95% confidence interval in parentheses:

22.4: 5.8 (3-22)

Hey @Feniks Technologies, how are the numbers in parenthesis interpreted? Can you explain that at bit for us dimwitted folk?

 

[b6graham]

Hey @Feniks Technologies, how are the numbers in parenthesis interpreted? Can you explain that at bit for us dimwitted folk?

The numbers in parentheses is the range your SD is 95% likely to fall into over the long haul.

 

[OREGUN]

Range. I missed that piece. Thanks

 

[Dogtown]

If you look at an SD (Normal Distribution) curve, think of the Confidence Interval as a section of range under that curve. A 95% CI just ignores the extremes +/- 5% and basically says 95% of all values will be within that range. There’s a simple function on any graphing calculator that can do this, given a series of values.

 

[Feniks Technologies]

Range. I missed that piece. Thanks

Ya. In plain speak, it’s a fairly good prediction of the range the actual SD of that load is. Based on the sample data.

Where this really helps is when you have something like couple 5 shot strings with different charge weight. One is a 5sd and the other is an 8sd.

Their confidence range overlaps so much, that based on the available data, they are too close to consider one better than the other.

Obviously you could choose the 5sd and barely be ahead in the odds that it *may* be the better of the two. However, it’s not more likely than not based on available data.

It’s also important when your 5sd turns into 13sd in a week or three. Most will panic and think “my load fell apart.” When in reality, the 95% confidence range was 3-14fps. So the ammo is performing inside expectations.


On another level, that’s why understanding SD highlights some of the issues with relying on your ES. They go hand in hand.

95% of the time, your ES is 4 times your SD.

So, if you have a 5 shot 5sd, that puts your 95% sd interval at 3-14fps.

That means that load could have an ES of up to 56fps 95% of the time. And up to 84fps 5% of the time.


In a nut shell, since it’s so common to see 5 shot strings with a 5sd or so posted online, that’s a very good reference.

When you see that on your chrono, realize that 5sd could easily be up to 14sd and up to 56-84fps ES. It’ll save you a lot of heartache.

 

[tstanek]

Hi guys,
so I had loaded 23,6 23,7 and 23,8 Gr, 5 rounds each, and shot it without magneto and bipod. Again indoor range, (no wind), 110 yards, reloading process totally the same (similar box of bullets and batch of prepped brass, etc...). I guess I pulled / failed some of the shots, It was partly cause my shooting, partly cause of air conditioning / ventilation of the range wasn't working properly and It was like shooting in some kind of mist and the targets were blurry 23,6 group is sticked there because I accidentaly shot another paper, but It was right next to proper one in the same height. I'm not satisfied with the result ofc. What do you think about it? Anything could be taken from this? Thanks a lot in advance for any comments.

EDIT. I uploaded another photo with one inch on caliper and 223 round for comparison.

 

[straightshooter1]

Hi guys,
so I had loaded 23,6 23,7 and 23,8 Gr, 5 rounds each, and shot it without magneto and bipod. Again indoor range, (no wind), 110 yards, reloading process totally the same (similar box of bullets and batch of prepped brass, etc...). I guess I pulled / failed some of the shots, It was partly cause my shooting, partly cause of air conditioning / ventilation of the range wasn't working properly and It was like shooting in some kind of mist and the targets were blurry 23,6 group is sticked there because I accidentaly shot another paper, but It was right next to proper one in the same height. I'm not satisfied with the result ofc. What do you think about it? Anything could be taken from this? Thanks a lot in advance for any comments.

EDIT. I uploaded another photo with one inch on caliper and 223 round for comparison.

Well, I still feel the best you're getting is the 23.6. I'm seeing the vertical as being best with that load and the horizontal with it is very likely your shooting mechanics, IMHO. That's all I can get out of the two sessions you've posted. With the MagnetoSpeed off, I would have like to seen a charge or two less than the 23.6. Anyhow, you might now start a test for seating depth with that load to see if you can tighten the group up???

 

[tstanek]

Thanks Sir. Yep that is what I'm thinking of doing next, but I'm little skeptical about that. I have never had much luck with S.D. tweaking when comes to reloading for my AR15 tbh. But it's def worth to give it a try I guess.

P.S. I will also load 5 of 23,5 Grs I suppose.

And I have one more question - what could really be expected from an 18 ' AR15 in terms of group size etc. at this distance, witht this particular bullet / 69 Gr bullets in general? I mean if shot by good shooter and there would be minimal human error...

 

[Rocketmandb]

Hi guys,
so I had loaded 23,6 23,7 and 23,8 Gr, 5 rounds each, and shot it without magneto and bipod. Again indoor range, (no wind), 110 yards, reloading process totally the same (similar box of bullets and batch of prepped brass, etc...). I guess I pulled / failed some of the shots, It was partly cause my shooting, partly cause of air conditioning / ventilation of the range wasn't working properly and It was like shooting in some kind of mist and the targets were blurry 23,6 group is sticked there because I accidentaly shot another paper, but It was right next to proper one in the same height. I'm not satisfied with the result ofc. What do you think about it? Anything could be taken from this? Thanks a lot in advance for any comments.

EDIT. I uploaded another photo with one inch on caliper and 223 round for comparison.

Why no chrono info? Chrono every shot at this stage of the game.

 

[tstanek]

I have just Magnetospeed, without off-barrel mount, no Labradar ...

 

[Feniks Technologies]

If you’re going to use chrono for load development, you have to stick with the chrono until you have chosen a powder charge. If you only have a magneto, this means you’ll have to have separate processes.

Let’s say you shoot 10 charge weights, 5 shots each. And you narrow it down to 3 charge weights. And you want to make sure they are g2g or test smaller increments.

You’ll need to go back and shoot the 3 charges over the chrono.

Once you have decided on charge weight, then work on seating depth without the chrono.

Or, do pick a random charge first and do seating and then do powder with chrono.



You’re mixing processes and testing the wrong things with the wrong test. Powder with chrono and seating depth with paper.

Otherwise you’re just going to be wasting ammo without any real data to speak of (and even then, depending on results, you may not have much valuable data).

 

[Feniks Technologies]

If you want to test charge weights via shooting paper, you’ll need to do something like an OCW test. That’s a whole other conversation on the validity of different methods.

But what you’re doing here is taking the wrong parts from different methods and combining them incorrectly.

 

[straightshooter1]

If you’re going to use chrono for load development, you have to stick with the chrono until you have chosen a powder charge. If you only have a magneto, this means you’ll have to have separate processes.

Let’s say you shoot 10 charge weights, 5 shots each. And you narrow it down to 3 charge weights. And you want to make sure they are g2g or test smaller increments.

You’ll need to go back and shoot the 3 charges over the chrono.

Once you have decided on charge weight, then work on seating depth without the chrono.

Or, do pick a random charge first and do seating and then do powder with chrono.



You’re mixing processes and testing the wrong things with the wrong test. Powder with chrono and seating depth with paper.

Otherwise you’re just going to be wasting ammo without any real data to speak of (and even then, depending on results, you may not have much valuable data).

For the most part, I do agree with what you're saying and why I find it's best not to use the MagnetoSpeed until after I've found a good accuracy load and seating depth. However . . . I have found that I can get in the ballpark with my MagnetoSpeed attached and narrow the loads down to a spread I can work with without the M-Speed and then work on the seating depth. Group sizes with my M-Speed attached are very close to what I get without it and it's just the POI that's significantly different.

As far as a waist of ammo, I just don't find it's a total waist of ammo nor without any real data (like getting velocity to start with), though I don't feel that's the best time for it. I guess it depends on how one manages their data???

 

[straightshooter1]

And I have one more question - what could really be expected from an 18 ' AR15 in terms of group size etc. at this distance, witht this particular bullet / 69 Gr bullets in general? I mean if shot by good shooter and there would be minimal human error...

It really depends on a lot of variables other than a good precision loaded cartridge (e.g. optics, trigger and barrel). Mostly, it depends on the quality of the barrel, which I'd expect to get sub 1/2" @ 100yds. With a factory barrel, more like 1 - 1.5". . . but if one happens to get really lucky with a factory barrel, then maybe down to 1/2". I don't shoot AR's, though quite a few of my shooting buddies do. So, I say that solely on my observation and talking with them. Maybe someone else can give you details about their own experience.

 

[MarshallDodge]

I am pretty happy with an AR barrel if it will shoot .75 MOA or less, but most of the variation is probably me.

 

[tstanek]

I must admit I kinda got "inspiration" of doing so from this vid - .

So what do you suggest is to load 23,6 ,7 ,8 and measure velocities? For 23,6 it was basically done in first (previous) test. What would I get from that further measurements I'm not sure...? I'm not aiming for specific velocity level, just for smaller groups. But I completely understand and agree to what you are saying. I do know it's wrong to do / change 2 or more parameters at one time when comes to realoding. Just this development is focused primarily on groups size / charge, those speeds I measured I thought I would maybe, or maybe not, somehow relate to the groups, but main point is to find charge which leads to the best group. I hope I explained myself at least a bit, sorry for bad English.

 

[straightshooter1]

I must admit I kinda got "inspiration" of doing so from this vid - .

So what do you suggest is to load 23,6 ,7 ,8 and measure velocities? For 23,6 it was basically done in first (previous) test. What would I get from that further measurements I'm not sure...? I'm not aiming for specific velocity level, just for smaller groups. But I completely understand and agree to what you are saying. I do know it's wrong to do / change 2 or more parameters at one time when comes to realoding. Just this development is focused primarily on groups size / charge, those speeds I measured I thought I would maybe, or maybe not, somehow relate to the groups, but main point is to find charge which leads to the best group. I hope I explained myself at least a bit, sorry for bad English.

Velocities to me are only good to know for making sure a bullet is stable out to long distance . . . AND, to tell me how well I'm loading my cartridges (e.g. my SD's and ES's). Otherwise, it's what I see on paper that tells me how well my load's are shooting. My SD's and ES's tend to be good (like single digit SD's) whether my loads perform well or not on paper and so I depend on this chrono data to tell me how well I'm reloading . . . not how well the loads work with my particular gun.

Here's a couple videos you may find of interest:

 

[tstanek]

Velocities to me are only good to know for making sure a bullet is stable out to long distance . . . AND, to tell me how well I'm loading my cartridges (e.g. my SD's and ES's). Otherwise, it's what I see on paper that tells me how well my load's are shooting. My SD's and ES's tend to be good (like single digit SD's) whether my loads perform well or not on paper and so I depend on this chrono data to tell me how well I'm reloading . . . not how well the loads work with my particular gun.

Here's a couple videos you may find of interest:

Thanks, will check it out ! seems very useful