Accuracy due to velocity, charge, or random...?

[ar10ar15man]

wow you spend a lot of money and time getting there.
to each their own.

To the OP. After 50+ years of rolling my own I have to admit I am still learning. Your original questions are valid and yes I can see and have been through your frustrations. Yes there are nodes, yes they are pretty easy to find, but everything has to be controlled & verified to find them.
A good chronograph is important but with long range ladders not a necessity. But the chronos can help verify the good, bad and ugly. Good meaning a magneto speed or labradar. An optical if setup right in optimal light conditions will also work. I used shooting chronies for years and learned when and when not they are useful.
As others said quality of test loads is the most important.
Equipment obviously has to be in its best mechanical condition (ie; action bedding & torque, scope bases & rings etc.)
Shooter & bench systems also proper repeatable form.
That being said start with your best load so far and do a complete seating test from .010 off the lands down to say .120 off using 3 shot groups in .010 increments. Shoot these round robin in a fouled barrel. Don't let the barrel get hot. Then run a second test starting at .015 off to say .125 off again in .010 increments, also round robin. Most likely you will see 2 or more seating nodes with each test. Pay attention to the smallest groups and their point of impact in relation to the others (No scope adjustments during these tests).
After seating tests the OCW or ladder test can commence for velocity. Start again with your "good" load and load say 5 or 6 in each direction at .2 or .3 grain increments. Shooting the 10 or 12 now at a longer distance ladder (300-400) will show possible velocity nodes by verticle impact also chrono readings will verify the node. I've always recorded velocities but lately been graphing results. Nodes are clearly visible on graphs not necessary but really tell you where you are at. Once you identify the node or nodes you are almost there. Now you can fine tune your seating in .003" increments both directions. As you leave the seating node your groups open.
This whole thread has provided a ton of great advice and we hope we have helped.
Good luck and keep us posted,
Randy

 

[entoptics]

...A good chronograph is important but with long range ladders not a necessity...

I use a LabRadar.

...As others said quality of test loads is the most important...

I weight sort, neck turn, hand weigh charges, and have runout at 0.002" or less.

...Equipment obviously has to be in its best mechanical condition (ie; action bedding & torque, scope bases & rings etc.)...

I do not have the money for much more than I run, but I have a torque wrench and know how to use it. My 300 WM does have a Shilen barrel installed, but is otherwise stock. I do have good optics and mounts. The rifle shoots more or less everything I feed it into 0.8 - 1.2 MOA. Those numbers are long term averages of 4 shot groups using half dozen 200 gr class projectile types (Best = 208 ELDM, worst = 212 ELDX. Berger, Accubond, and Sierra GK in the middle). There is no "if I do my part" or "this rifle is capable of" in my spreadsheet. What the calipers get is what is recorded.

...Shooter & bench systems also proper repeatable form...

I am above average, but nowhere near exceptional. Almost all shooting is done prone, bipod, rear bag. I have not seen measurably different group sizes in the few times a year I shoot from a concrete bench.

...That being said start with your best load so far and do a complete seating test......

Here are the results of a years worth of measured groups from 100-500 yds. All 208 ELDM, Fed 210M, H1000 with no more than ±0.75 gr changes in charge weight. They were not all intended as seating depth tests of course, but that is information that I record for every measured group. I did not include groups from days with poor weather or other confounding conditions (e.g. hunting practice in the wind).

...

After seating tests the OCW or ladder test can commence for velocity. Start again with your "good" load and load say 5 or 6 in each direction at .2 or .3 grain increments. Shooting the 10 or 12 now at a longer distance ladder (300-400) will show possible velocity nodes by verticle impact also chrono readings will verify the node. I've always recorded velocities but lately been graphing results. Nodes are clearly visible on graphs not necessary but really tell you where you are at....

Here's two recent tests I did. Velocities from LabRadar, and a target at 400 yds. There were no "nodes" in accuracy/drop, and as you can see, not much in the velocities either. I revisited the lower flattish area on the ELDX and got different results (the upper one was too hot for my taste). Unfortunately, I stupidly saved over my spreadsheet and lost the rest of the ELDM data and the revisited ELDX test. There was no identifiable node for the ELDM either, from 77.8 down to 75.1, but you'll have to take my word for it.

As mentioned, I have some experience with this. I do not deny that some folks see "nodes". I have not. I have also thoroughly proven to myself that it's unnecessary for my purposes. I still do it, simply because I'm a scientist, and enjoy applying that to my hobby. Many people forget that a null result is often just as important as a positive result.

 

[DUSTY NOGGIN]

View attachment 125417


View attachment 125418

looks like your graph data for 77.5 has flipped speeds for eldm & eldx ( the eldx2 to drop 60fps with a .3 increase -- with the eldm 1 to increase 80fps same area ) .. what is your best ES your getting, the eldm at 76. has a 25fps difference so id guess its the same even if randomly dropping em at closer speeds

maybe i reading your graph wrong. but,its good that you shot 2 of each bullet , to show that part ... alot of guys only shoot one and follow that random line through the middle of the ES (sometimes they get lucky , others wonder why it wont repeat)

i think if you find a way to lower that ES your graphs will also show , annealed ?? expander manual at seating ?? ...

 

[MNbogboy]

I use a LabRadar.
I weight sort, neck turn, hand weigh charges, and have runout at 0.002" or less.

I do not have the money for much more than I run, but I have a torque wrench and know how to use it. My 300 WM does have a Shilen barrel installed, but is otherwise stock. I do have good optics and mounts. The rifle shoots more or less everything I feed it into 0.8 - 1.2 MOA. Those numbers are long term averages of 4 shot groups using half dozen 200 gr class projectile types (Best = 208 ELDM, worst = 212 ELDX. Berger, Accubond, and Sierra GK in the middle). There is no "if I do my part" or "this rifle is capable of" in my spreadsheet. What the calipers get is what is recorded.

I am above average, but nowhere near exceptional. Almost all shooting is done prone, bipod, rear bag. I have not seen measurably different group sizes in the few times a year I shoot from a concrete bench.

Here are the results of a years worth of measured groups from 100-500 yds. All 208 ELDM, Fed 210M, H1000 with no more than ±0.75 gr changes in charge weight. They were not all intended as seating depth tests of course, but that is information that I record for every measured group. I did not include groups from days with poor weather or other confounding conditions (e.g. hunting practice in the wind).
View attachment 125417

Here's two recent tests I did. Velocities from LabRadar, and a target at 400 yds. There were no "nodes" in accuracy/drop, and as you can see, not much in the velocities either. I revisited the lower flattish area on the ELDX and got different results (the upper one was too hot for my taste). Unfortunately, I stupidly saved over my spreadsheet and lost the rest of the ELDM data and the revisited ELDX test. There was no identifiable node for the ELDM either, from 77.8 down to 75.1, but you'll have to take my word for it.
View attachment 125418

As mentioned, I have some experience with this. I do not deny that some folks see "nodes". I have not. I have also thoroughly proven to myself that it's unnecessary for my purposes. I still do it, simply because I'm a scientist, and enjoy applying that to my hobby. Many people forget that a null result is often just as important as a positive result.

I like your attention to detail and certainly your introduction didn't reflect your methods. My first post was not meant to condescend in any way. Your post now clarifies your methods and puts us all on the same page.
In my opinion the velocity graph shows 2 pretty distinct nodes for the eldx the first at 75.4 with only one outlier and 76.6 shows a perfect example of a node (I would use this and redo my seating). The elms however is somewhat inconclusive except 76.9 looks promising with 76.3 & 77.2 very close. There may be something at around 76.0 also (eldm2 could be a fluke). I would rerun 75.1 all the way to 77.5 with both bullets to see if these patterns repeat.
The seating graph however is a little different to decipher. Without seeing side by side groups & their shapes and point of impacts. Obviously certain seating depths on your chart shows scatter nodes as groups really open up. The other thing on the seating graph is the .020 increment may let you pass by what the each bullet really likes resulting with no definitive results. Seating nodes are often narrow (plus or minus .003 is common).
Seating depth unless magazine length is the deciding factor will generally have more effect on group size in most barrels than the charge weight. That is where i usually start with new barrels. The brass will get fireformed during the process and by the time 100 or so rounds are thru the barrel the velocity has stabilized and final fine tuning can begin.
Good shooting.

 

[ar10ar15man]

not trying to be rude, but if you are only at 1moa at short range. things need to change.
you seem to have tools(bits and pcs) but the end results aint there.
prone is not as good as bench with a rest. lots chart and graphs, no results.
find someone that shoots very well and ask for help.
have you done a simple ladder test at 200 yards ?
single shots, 1/100 case capacity step, 10 steps. start at .010 since it is a hunting rifle.
yes check velocity, but is also small vertical in groups.
look at groups
1,2
123
234
345
456
567
678
789
8910
910
way too many rounds down range with little return.
what is the scope ?

 

[MNbogboy]

wow you spend a lot of money and time getting there.
to each their own.

For the OP what I suggested was around a 100 rounds. Normally most barrels don't even stabilize velocity until then (keeps speeding up). And I buy brass in lots of 50 to 100, twice fireforming isn't too much. I would like to get there sooner but it takes what it takes.
There are some high dollar barrels out there that could take less break in with smaller amounts of brass but dollars are dollars and I like load development & shooting.

 

[entoptics]

looks like your graph data for 77.5 has flipped speeds for eldm & eldx ( the eldx2 to drop 60fps with a .3 increase -- with the eldm 1 to increase 80fps same area ) .. what is your best ES your getting, the eldm at 76. has a 25fps difference so id guess its the same even if randomly dropping em at closer speeds.

The data is not flipped. Not really sure what happened there.

My typical ES/SD for 8 rounds (2 groups) is ~20/10. With my new batch of sig brass, I only have 13 rounds downrange, with an ES of 17 and SD of 6.

not trying to be rude, but if you are only at 1moa at short range. things need to change.
you seem to have tools(bits and pcs) but the end results aint there.
prone is not as good as bench with a rest. lots chart and graphs, no results.
find someone that shoots very well and ask for help.
have you done a simple ladder test at 200 yards ?...
way too many rounds down range with little return.
what is the scope ?

I do not know anyone who can shoot better than me. I'm in a small town, so I'm unlikely to find anyone either.

I'm happy with my results. The rifle averages ~0.8 MOA with the ELDM all the way out to ~700 yds. It's actually averaging about 0.7 MOA at 1000 yds, but that's only from 3 measured groups, so it's pretty meaningless. My results on steel at that distance suggest a bit over an MOA or so (can get 9 outa 10 on a 16" plate on a calm day).

Most of the data presented is not from load development, it's from drop confirmation, temperature sensitivity experiments, and just plain old practice and fun.

Previously it was a Sig Tango4 6-24. That died a horrible death, and was replaced under warranty with a Whiskey 5-25, which seems peachy, but I've got less than 50 rounds with it.

For the OP what I suggested was around a 100 rounds. Normally most barrels don't even stabilize velocity until then (keeps speeding up)...and I like load development & shooting...

This barrel has ~1000 rounds on it, so I think it's broke in...This thread has drifted pretty far from my original query about new brass...

I too like experiments and shooting, so I'll likely revisit some of the ladder testing and seating. I'm fairly certain it will turn out like it has the dozen other times I've tried it, but I'll enjoy the process and maybe get lucky and find the elusive "node"...

 

[ar10ar15man]

i think you have pretty well documented that your process cannot identify a node.
get a real front rest and sit at a bench
else be happy in mediocre land.

The data is not flipped. Not really sure what happened there.

My typical ES/SD for 8 rounds (2 groups) is ~20/10. With my new batch of sig brass, I only have 13 rounds downrange, with an ES of 17 and SD of 6.

I do not know anyone who can shoot better than me. I'm in a small town, so I'm unlikely to find anyone either.

I'm happy with my results. The rifle averages ~0.8 MOA with the ELDM all the way out to ~700 yds. It's actually averaging about 0.7 MOA at 1000 yds, but that's only from 3 measured groups, so it's pretty meaningless. My results on steel at that distance suggest a bit over an MOA or so (can get 9 outa 10 on a 16" plate on a calm day).

Most of the data presented is not from load development, it's from drop confirmation, temperature sensitivity experiments, and just plain old practice and fun.

Previously it was a Sig Tango4 6-24. That died a horrible death, and was replaced under warranty with a Whiskey 5-25, which seems peachy, but I've got less than 50 rounds with it.

This barrel has ~1000 rounds on it, so I think it's broke in...This thread has drifted pretty far from my original query about new brass...

I too like experiments and shooting, so I'll likely revisit some of the ladder testing and seating. I'm fairly certain it will turn out like it has the dozen other times I've tried it, but I'll enjoy the process and maybe get lucky and find the elusive "node"...

 

[MNbogboy]

For the OP what I suggested was around a 100 rounds. Normally most barrels don't even stabilize velocity until then (keeps speeding up). And I buy brass in lots of 50 to 100, twice fireforming isn't too much. I would like to get there sooner but it takes what it takes.
There are some high dollar barrels out there that could take less break in with smaller amounts of brass but dollars are dollars and I like load development & shooting.

Entoptics,
I guess I wrote that one wrong. Intended for ar10 when he thought I was wasting ammo. What I meant to say to him is what I had suggested to you was only 100 rounds.
I am sure that some may find a load with less. But covering all the bases the first time won't leave you wondering if something was left on the table.
Also sorry about missing your point about the load matching with brass change. I was concentrating on the "node" issue.
Finally, es/sd numbers like your last 17/6 should be all you expect. I have found grouping troubles with good numbers that could not be attributed to mechanical but just the barrel characteristics with that cartridge and load. Powder, primer, brass, bullet nothing got it to shoot. Faced it off rechambered it from 6.5-06 to 6.5/257 Bob AI. It went from 3/4 minute to 5/8. Set it back again and chambered it to Creedmoor. It now shoots like a house on fire .19, .28 & .33 last time out a -4F @ 100. I know it will be a true 1/2 moa all day barrel for what's left of it. Point is you can do everything right and it is possible the barrel isn't ever going to get any better.

 

[crkckr]

Bogboy said "Point is you can do everything right and it is possible the barrel isn't ever going to get any better."

Oh man, truer words have never been spoken!
Cheers,
crkckr

 

[Innovative]

A rocket scientist might care about "nodes", because they do exist.

However, a shooter only needs to be concerned with finding the particular velocity that allows each different bullet fly best. If you can't make a particular bullet shoot well enough; try a different bullet, and then see what velocity makes that bullet perform best.

Make sure you select a bullet that is compatible with your rifling twist rate. Most bullet manufacturers can tell you their best bullet to use with your particular barrel. My 300 Win Mag does best with the Berger 210 gr "Hunting Bullet" pn# 30415.