Why is it impossible to duplicate a great shooting load?

[sig2009]

Had a couple great loads last week 5 shots thru one hole. This week I load up the same and as usual both suck on paper. In the past 6 months I have only been able to duplicate one load, and that load I repeated 3 more times. And it continues to shoot great. Nothing changes. Same brass and prep. Annealed. Full length sized. Shoulders bumped .002. All trimmed to same length. Mandrel used to set neck tension. Same seating depth. Same GMM primers. Primer pockets cleaned. Same powder charge double checked on the A&D scale. And also as usual the other loads I tested with single digit SD/ES shot the worst. Am I missing something here?

 

[OREGUN]

Not sure I follow. Your 5 shot, one hole load is good one day and not the next but you are pretty sure that at least in some cases your goodest load is good all the time?

Don’t be fooled by statistics. It takes a lot of shots to really verify both groups and SDs. Like 20, as a minimum, to have faith in an SD. As for group sizes, position, parallax, lighting, temperature (not because of burn rate but rather because of your breathing/clothing/ability to relax behind the gun), caffeination, stress, etc. can all change your groups size day to day. Shoot from several different positions or at least on several different days if you’re a prone only guy, to really see what the groups sizes look like.

Your loading sounds ok. Might try a different type of primer if you can. Low SDs doesn’t always mean small groups at 100.

Clean the gun (and then shoot at least 5 to “foul it”), make sure nothing is loose (action screws, mount screws, etc), try again focusing on fundamentals. If it shoots good on the third day, it’s you, not the load.

Thats my two cents.

 

[nn8734]

Had a couple great loads last week 5 shots thru one hole. This week I load up the same and as usual both suck on paper. In the past 6 months I have only been able to duplicate one load, and that load I repeated 3 more times. And it continues to shoot great. Nothing changes. Same brass and prep. Annealed. Full length sized. All trimmed to same length. Mandrel used to set neck tension. Same seating depth. Same GMM primers. Primer pockets cleaned. Same powder charge double checked on the A&D scale. And also as usual the other loads I tested with single digit SD/ES shot the worst. Am I missing something here?

My guess: You executed the fundamentals of marksmenship perfectly on those one-hole groups and not any of the others.

 

[wade2big]

What does the good load look like on paper when it no longer is considered good? Goes from one hole to what? Are you shooting multiple one hole groups over and over again when it’s good and multiple bad groups when it’s bad? Seems strange you have a good load that stops being good the next day.

 

[sig2009]

What does the good load look like on paper when it no longer is considered good? Goes from one hole to what? Are you shooting multiple one hole groups over and over again when it’s good and multiple bad groups when it’s bad? Seems strange you have a good load that stops being good the next day.

At least 1" MOA.

 

[M4orturnate]

Could be right on the edge of a node wether its powder or seating depth. One day its light out then temp changes 15 degrees and it sucks. Theres a reason we look for long stable nodes even with temp stable powder

 

[W54/XM-388]

Is there a time frame between when you load and when you shoot?
Did a significant amount of time transpire between when you originally shot the really good load and when you shot the rest of it and the groups sucked?

 

[wade2big]

Is there a time frame between when you load and when you shoot?
Did a significant amount of time transpire between when you originally shot the really good load and when you shot the rest of it and the groups sucked?

You asked more than one question at a time like I did. He will only answer one.

 

[sig2009]

Not sure I follow. Your 5 shot, one hole load is good one day and not the next but you are pretty sure that at least in some cases your goodest load is good all the time?

Don’t be fooled by statistics. It takes a lot of shots to really verify both groups and SDs. Like 20, as a minimum, to have faith in an SD. As for group sizes, position, parallax, lighting, temperature (not because of burn rate but rather because of your breathing/clothing/ability to relax behind the gun), caffeination, stress, etc. can all change your groups size day to day. Shoot from several different positions or at least on several different days if you’re a prone only guy, to really see what the groups sizes look like.

Your loading sounds ok. Might try a different type of primer if you can. Low SDs doesn’t always mean small groups at 100.

Clean the gun (and then shoot at least 5 to “foul it”), make sure nothing is loose (action screws, mount screws, etc), try again focusing on fundamentals. If it shoots good on the third day, it’s you, not the load.

Thats my two cents.

My best load I worked up a couple months ago continues to shoot one hole My thought is the barrel likes the heavier 147gn bullets and the majority of the 140's I've loaded mostly suck. I actually was under the false impression also that Bartlein was supposed to be great shooting barrelsa barrels. So far up to this point it's not the case.

 

[sig2009]

Is there a time frame between when you load and when you shoot?
Did a significant amount of time transpire between when you originally shot the really good load and when you shot the rest of it and the groups sucked?

I load up each week probably Wed and hit the range on Sat.

 

[Precision Underground]

Had a couple great loads last week 5 shots thru one hole. This week I load up the same and as usual both suck on paper. In the past 6 months I have only been able to duplicate one load, and that load I repeated 3 more times. And it continues to shoot great. Nothing changes. Same brass and prep. Annealed. Full length sized. All trimmed to same length. Mandrel used to set neck tension. Same seating depth. Same GMM primers. Primer pockets cleaned. Same powder charge double checked on the A&D scale. And also as usual the other loads I tested with single digit SD/ES shot the worst. Am I missing something here?

How are you finding these loads? It’s not likely that a Bartlein barrel is the problem but anything is possible. Do you have other rifles that you shoot well consistently?

 

[sig2009]

Not sure I follow. Your 5 shot, one hole load is good one day and not the next but you are pretty sure that at least in some cases your goodest load is good all the time?

Don’t be fooled by statistics. It takes a lot of shots to really verify both groups and SDs. Like 20, as a minimum, to have faith in an SD. As for group sizes, position, parallax, lighting, temperature (not because of burn rate but rather because of your breathing/clothing/ability to relax behind the gun), caffeination, stress, etc. can all change your groups size day to day. Shoot from several different positions or at least on several different days if you’re a prone only guy, to really see what the groups sizes look like.

Your loading sounds ok. Might try a different type of primer if you can. Low SDs doesn’t always mean small groups at 100.

Clean the gun (and then shoot at least 5 to “foul it”), make sure nothing is loose (action screws, mount screws, etc), try again focusing on fundamentals. If it shoots good on the third day, it’s you, not the load.

Thats my two cents.

Yes. I was going to swap out to some CCi Br's and rerun them.

 

[918v]

Did u clean your barrel in between? How many shots on the barrel? How many shots before your unicorn group? Did you fire that many shots that day before trying to replicate the group?

 

[sig2009]

How are you finding these loads? It’s not likely that a Bartlein barrel is the problem but anything is possible. Do you have other rifles that you shoot well consistently?

My other 6.5 bolt rifle has a Rock Creek barrel and Tikka action and I think it shoots better. I find the loads by going in 2/10 grain increments. My current rifle with the Bartlein is a Terminus Zeus action.

 

[never_summer]

Have you gone through a tightness check or verified your scope? I had a cracked scope mount on the clamp bar that was only visible once I looked from the front and inside.
Long story short it would shoot poor but not horrible, sporadic 1 moa groups. But would shoot some small groups in between and always had the same shift horizontally on the bad groups.

 

[sig2009]

Did u clean your barrel in between? How many shots on the barrel? How many shots before your unicorn group? Did you fire that many shots that day before trying to replicate the group?

It was actually the first 5 shots of the day. Just looked 160 rounds today before I started. I normally clean it every 200 rounds. Many pros and cons to barrel cleaning. I'm just not one who thinks you should clean it after every range trip. Even Eric Cortina usually goes 200 rounds before cleaning.

 

[sig2009]

Have you gone through a tightness check or verified your scope? I had a cracked scope mount on the clamp bar that was only visible once I looked from the front and inside.
Long story short it would shoot poor but not horrible, sporadic 1 moa groups. But would shoot some small groups in between and always had the same shift horizontally on the bad groups.

I'll check that tomorrow.

 

[918v]

It was actually the first 5 shots of the day. Just looked 160 rounds today before I started. I normally clean it every 200 rounds. Many pros and cons to barrel cleaning. I'm just not one who thinks you should clean it after every range trip. Even Eric Cortina usually goes 200 rounds before cleaning.

Maybe you should clean and then try to replicate the group.

 

[sig2009]

Maybe you should clean and then try to replicate the group.

Ya. I plan on that tomorrow.

 

[diggler1833]

Could be right on the edge of a node wether its powder or seating depth. One day its light out then temp changes 15 degrees and it sucks. Theres a reason we look for long stable nodes even with temp stable powder

^ This is my guess as well.

 

[918v]

Ya. I plan on that tomorrow.

I have found that on high round count barrels I have to clean more frequently to maintain accuracy and it takes more “fouling“ rounds to get a dirty barrel grouping well when I don’t clean prior to shooting again. But once it’s warmed up it shoots great.

 

[OREGUN]

What powder and caliber/cartridge are we talking about?

 

[OREGUN]

What size barrel (contour)? Your good group was the first five on that barrel?

 

[straightshooter1]

Had a couple great loads last week 5 shots thru one hole. This week I load up the same and as usual both suck on paper. In the past 6 months I have only been able to duplicate one load, and that load I repeated 3 more times. And it continues to shoot great. Nothing changes. Same brass and prep. Annealed. Full length sized. Shoulders bumped .002. All trimmed to same length. Mandrel used to set neck tension. Same seating depth. Same GMM primers. Primer pockets cleaned. Same powder charge double checked on the A&D scale. And also as usual the other loads I tested with single digit SD/ES shot the worst. Am I missing something here?

Hmmm??? A lot of interesting responses here and not many questions about other issues that can be a play.

You haven't provided any velocity info and I guess we're to assume your MV were all the same.

You haven't said what temperatures you've shot in or other conditions you were shooting in. Difference there can make all the difference.

While you're using the same powder, there can be a significant difference in moisture content over 6 months (depending non how it's handled) and that would show up in velocity differences and changes in SD's and ES's.

If you're not using the same bullets from the same lot, there could be substantial difference in actual seating depth, particularly if you're measuring seating depth by CBTO. Depending on the quality of the bullet manufacturer, there's could be substantial differences within the same lot to change things up.

Regarding Eric Cortina: I do recall him going 200 rounds or so before cleaning. . .like after a day's outing. On more than one occasion he's stated that he cleans after every outing at a range, which could be 50 rounds, 100 or 200 rounds. But apparently, he doesn't make it a habit of going high round counts before cleaning.

. . . lots of unknown info concerning the things that could be at play for what's going on with such a change.

 

[Bacarrat]

How did you get the load you are shooting now? How did the other loads around it shoot? I use to hate load developing as thought it was a waste of components. I would do load charge ups and if a load shot well that day, I would go with that. Sometimes it would work on the confirmation trip to the range. But now I when I do load development, I try to see if it's a one off load or am I in a node or range of where I should be at in the powder charge. Now I just look for a node of powder charges were the ES and SD were low and just do seating depth charges from there to find it and confirm the load. A lot more components are used but the loads have been stable with a lot of the other variables you run into.

 

[Precision Underground]

My other 6.5 bolt rifle has a Rock Creek barrel and Tikka action and I think it shoots better. I find the loads by going in 2/10 grain increments. My current rifle with the Bartlein is a Terminus Zeus action.

I meant what’s your process for finding the load. Are you picking the best group from the test charges?

 

[sig2009]

What powder and caliber/cartridge are we talking about?

6.5 Creedmoor. H4350.

 

[sig2009]

I meant what’s your process for finding the load. Are you picking the best group from the test charges?

What size barrel (contour)? Your good group was the first five on that barrel?

Heavy contour. Correct first 5 shots of that day.

 

[sig2009]

I meant what’s your process for finding the load. Are you picking the best group from the test charges?

Started at 40.5 and worked up to 42.5 in 2/10's increments.

 

[Bacarrat]

You're within the ball park on the charge. Hornady use to publish the load on their box of ammo. 41.5gr of H4350 with the 140gr ELDMs. My previous Bartlein would shoot anything from 41.5 to 43.gr H4350. My new Proof would do the same too. Sounds like you have everything right and have all good rifle and ammo components. But what are your expectations? To shoot 1 hole groups all day? People lie about that part. lol Have you checked the rest of the gun? Scope rings, crown, action tight, bipod not loose, ect.

 

[db2000]

Sell the rifle and include that one hole target

 

[918v]

Ya. I plan on that tomorrow.

Well???

 

[sig2009]

Well???

Well what? Rifle is cleaned and everything is tight.

 

[918v]

So what do I win?

 

[acudaowner]

not at all depending on what your looking for we have 8 different powders we use that with different loads that give within a few fps of each other that all give about the same results ( stats ) .all give me about the same while not exactly the same when you average all those numbers out it's close enough to be called the same groups are a totally different matter cause no matter how I try I am never the exact same every shot and normally the weather changes slightly different min to min . but isn't that why you practice to know when to hold em , know when to show em , know when to walk away and to know how to run sorry had to add that .

 

[MarkyMark007]

Am I missing something here?

you are missing statistics. if you want to be sure how your load is good, shoot 30 shots.

people have good 5-shot groups and bad 5-shoot groups all the time with SAME load, but they lie about bad ones and say 'this is me' and 'this was a flyer'.

if you want REALY good load, shot 20+ shots and see how big is this group. 5-shot group is statistical lie, which is sometimes a good, and other time bad.

 

[BuildingConceptsllc]

you are missing statistics. if you want to be sure how your load is good, shoot 30 shots.

people have good 5-shot groups and bad 5-shoot groups all the time with SAME load, but they lie about bad ones and say 'this is me' and 'this was a flyer'.

if you want REALY good load, shot 20+ shots and see how big is this group. 5-shot group is statistical lie, which is sometimes a good, and other time bad.

This is fact. A 5 shot group tells you basically nothing. 20 shots min to know anything about your load, especially when it comes to SD/ES.

 

[Doom]

OP, what is your process for analyzing your targets?

 

[Molon]

Could be right on the edge of a node . . .

A load that is “right on the edge” of falling apart is the exact opposite of what an accuracy node is supposed to be. An accuracy node should have a “buffer” on either side of the nominal powder charge and still be able to produce precise radial dispersions and consistent central points of impact in those buffer zones. If it doesn’t, it’s really not much of a node.

The graphic below shows a 20-shot composite group that was fired in a round-robin sequence on four different targets using four different powder charges. The rounds were fired from a semi-automatic AR-15 at a distance of 100 yards.

A single shot from each of the four different powder charges of 23.2, 23.4, 23.6 and 23.8 grains was fired in a round-robin sequence on four different targets forming 4 separate groups of 5 shots each. Those groups were over-layed on the aiming point using the OnTarget software program. The extreme spread for the entire 20-shot composite group was 0.71 MOA with a mean radius of 0.23”.

A single 10-shot group fired from the semi-automatic AR-15 using the median accuracy node powder charge of 23.5 grains, which gives the load a "breathing space" of 0.6 grains (plus or minus 0.3 grains) had an extreme spread of 0.467 MOA. The mean radius for that group was 0.17”.

.......

 

[Vodoun daVinci]

Have you gone through a tightness check or verified your scope? I had a cracked scope mount on the clamp bar that was only visible once I looked from the front and inside.
Long story short it would shoot poor but not horrible, sporadic 1 moa groups. But would shoot some small groups in between and always had the same shift horizontally on the bad groups.

I had a situation where I figured out a load and then slowly I'd get erratic accuracy - one group .5 MOA @ 100 yards. The next group 3 shots in the same hole and the other 2 would be 1" or more *anywhere* else. Was driving me nuts literally for weeks. So then after a particularly bewildering group at the range I decided to just dry fire for a while and really work on doing the same thing every time. Then when I had the gun solidly on target and the bipod loaded, I pulled the trigger and it went *snap* and the sight picture moved. A lot. I thought what the fuck, am I flinching?

Tried it again no problem...then again and the sight pix thru the scope literally jump and inch off POA. I grabbed the scope and flexed it hard and the rail shifted enough I could feel it. Took her home and pulled the scope and the rail was sliding even though the screws were tight. Tore it all out, bedded the scope rail, bought new screws, reset it all with Loc-Tite. Re zeroed and it has been fabulous ever since.

VooDoo

 

[M4orturnate]

A load that is “right on the edge” of falling apart is the exact opposite of what an accuracy node is supposed to be. An accuracy node should have a “buffer” on either side of the nominal powder charge and still be able to produce precise radial dispersions and consistent central points of impact in those buffer zones. If it doesn’t, it’s really not much of a node.

The graphic below shows a 20-shot composite group that was fired in a round-robin sequence on four different targets using four different powder charges. The rounds were fired from a semi-automatic AR-15 at a distance of 100 yards.

A single shot from each of the four different powder charges of 23.2, 23.4, 23.6 and 23.8 grains was fired in a round-robin sequence on four different targets forming 4 separate groups of 5 shots each. Those groups were over-layed on the aiming point using the OnTarget software program. The extreme spread for the entire 20-shot composite group was 0.71 MOA with a mean radius of 0.23”.

A single 10-shot group fired from the semi-automatic AR-15 using the median accuracy node powder charge of 23.5 grains, which gives the load a "breathing space" of 0.6 grains (plus or minus 0.3 grains) had an extreme spread of 0.467 MOA. The mean radius for that group was 0.17”.

.......

I get it. Ive ran into this when getting a new rifle and try to rush load dev for a match. Get it to shoot one hole quickly then load up 250 get to the match and that load now shoots 1.5 moa. I wont do it again. If a load is 100% ready, tested, and doped ill use a different reliable rifle and load.

 

[smoothy8500]

A single shot from each of the four different powder charges of 23.2, 23.4, 23.6 and 23.8 grains was fired in a round-robin sequence on four different targets forming 4 separate groups of 5 shots each. The extreme spread for the entire 20-shot composite group was 0.71 MOA with a mean radius of 0.23”

Sooooo, somebody please tell me again why I need a high-dollar powder meter that is accurate to 0.01gr or half a kernel of powder......

 

[MarkyMark007]

Sooooo, somebody please tell me again why I need a high-dollar powder meter that is accurate to 0.01gr or half a kernel of powder......

only for long range.

 

[MarkyMark007]

A load that is “right on the edge” of falling apart is the exact opposite of what an accuracy node is supposed to be. An accuracy node should have a “buffer” on either side of the nominal powder charge and still be able to produce precise radial dispersions and consistent central points of impact in those buffer zones. If it doesn’t, it’s really not much of a node.

The graphic below shows a 20-shot composite group that was fired in a round-robin sequence on four different targets using four different powder charges. The rounds were fired from a semi-automatic AR-15 at a distance of 100 yards.

A single shot from each of the four different powder charges of 23.2, 23.4, 23.6 and 23.8 grains was fired in a round-robin sequence on four different targets forming 4 separate groups of 5 shots each. Those groups were over-layed on the aiming point using the OnTarget software program. The extreme spread for the entire 20-shot composite group was 0.71 MOA with a mean radius of 0.23”.

A single 10-shot group fired from the semi-automatic AR-15 using the median accuracy node powder charge of 23.5 grains, which gives the load a "breathing space" of 0.6 grains (plus or minus 0.3 grains) had an extreme spread of 0.467 MOA. The mean radius for that group was 0.17”.

.......

so you perfectly demonstrated that 'node' is a mith and it exists only in our heads.

 

[supercorndogs]

so you perfectly demonstrated that 'node' is a mith and it exists only in our heads.

I thought you couldn't prove anything with 20 shots....

"Myth"

 

[Molon]

so you perfectly demonstrated that 'node' is a mith and it exists only in our heads.

That is absolutely not what I said. The data I posted was from a longer round-robin sequence in which the radial dispersion increased and the central points of impact shifted on both ends of the data points that I showed.