How to choose! 6.5cm Load Development

[Sniper1*]

Trying this again with more information that will hopefully help clarify some things.

Rifle and Setup -
Bergara B-14 HMR barreled action in a KRG Bravo Chassis
Nightforce NXS 3.5x15, Vortex PMR Rings

RCBS Rockchucker Press

Hornady Brass, Once Fired, 1 Deprimed, 2 Primer Pocket Cleaned, 3 Flash Hole Uniformed, 4 Wet tumbled, 5 Washed and dried, 6 Sized (FL Hornady Matchmaster Die) 0.288" Neck Bushing (giving me about .004" neck tension from my measurements), 7 Trimmed with Hornady LnL Trimmer to 1.920" or just under by a couple of thousands, 8 Case Mouth Deburred in/out

Bullet is the Hornady 135grain A-tip loaded to maximum mag length (I don't have my notes handy for the CBTOg measurement but I know it's 0.086" jump). Loaded with the Hornady Matchmaster Micrometer Die.

Primer - Federal 210

Powder RL16, initial charge dispensed by RCBS Chargemaster and then each verified with a beam-scale and adjusted appropriately to be precise.

Loads - 42.4, 42.6, 42.8, 43, 43.2, 43.4 (Three of each)

LabRadar for the numbers
Shot from a table top with bag supports

See the targets below for more information on FPS, ES, SD, and Group Size

If I missed something, let me know!


Original Post:::

"Question for the SME's! I'm working on a load for my 135gr A-tips in my 6.5cm. I'm running RL16 because it's what I have at the moment and realized I can get faster MV out of RL26 or maybe something else.

Let's just go with what I have rather than "use this" or "use that".

Based on the numbers and group sizes, which would you choose to run with?

Yes Shooter error could account for some deviation on either group (like the one shot to the right on 42.8).

I have the bullets loaded as long as I can possibly get with the mag length and already having to dremel out a spot in the feed ramp area to clear the tip of the bullet. With that tidbit of information I still have about 0.086" jump with the long chamber apparently.

Thoughts?"

 

[spife7980]

How would we possibly be able to tell anything with basically zero information provided from which to draw conclusions?

 

[Sniper1*]

How would we possibly be able to tell anything with basically zero information provided from which to draw conclusions?

What else is there that you would like to know? Caliber Information, Bullet information, Powder information, Seating information, Group information, MV information, ES information, SD information.... What am I missing? I have other groups and load info but these were the two best....

 

[Foul Mike]

Maybe shoot more than 3 to get the results you need? Like warming the barrel up with 5 shot from cold bore then wait a day and do 5 shots from cold bore with the other load?
With .2 gr. difference in the loads I doubt there will be a huge difference but I might be wrong.

 

[spife7980]

What else is there that you would like to know?

The load development part you asked about.

Based on what you have presented I would say neither and to go back to the drawing board.

 

[Sniper1*]

Maybe shoot more than 3 to get the results you need? Like warming the barrel up with 5 shot from cold bore then wait a day and do 5 shots from cold bore with the other load?
With .2 gr. difference in the loads I doubt there will be a huge difference but I might be wrong.

Yeah I think I will do that and maybe throw a 42.7gr in there as well to see what happens. Thanks

 

[918v]

Your groups indicate your load needs adjustment (case prep or powder/coal) or that you suck at aiming or pulling the trigger.

 

[Sniper1*]

The load development part you asked about.

View attachment 8005411

Based on what you have presented I would say neither and to go back to the drawing board. Thats a big shift between 2 tenths of a grain.

Ummmm....

So, I went from 42.4gr to 43.4gr of RL16 in .2gr increments! I only posted the two best groups with the numbers (42.6 and 42.8 as seen on the pics of the targets). CBTOg is kind of irrelevant due to they were all the same during this part and as stated loaded as long as I can possibly get with 0.086" jump.

and if "go back to the drawing board" is the best advice you have, maybe your aren't the SME I'm looking for.... Thanks for your time.

 

[spife7980]

Ummmm....

So, I went from 42.4gr to 43.4gr of RL16 in .2gr increments! I only posted the two best groups with the numbers (42.6 and 42.8 as seen on the pics of the targets). CBTOg is kind of irrelevant due to they were all the same during this part and as stated loaded as long as I can possibly get with 0.086" jump.

and if "go back to the drawing board" is the best advice you have, maybe your aren't the SME I'm looking for.... Thanks for your time.

And so you chose the two tenths spread with a half moa shift between six shots for the two of them and think we will be able to guide you on this? Im all for donating time to help someone but you have to give us something to work with. At least show us what the only one grain spreads worth of targets looks like.

 

[37L1]

Go back, fire at 200 yards, 5 shot groups, more than one per load.

That will tell you more than you are getting now.

 

[Sniper1*]

Your groups indicate your load needs adjustment (case prep or powder/coal) or that you suck at aiming or pulling the trigger.

Rough place today! Good thing I'm thick skinned and have zero issues with my skillset otherwise I might be offended by your comment!

 

[Sniper1*]

And so you chose the two tenths spread with a half moa shift between six shots for the two of them and think we will be able to guide you on this? Im all for donating time to help someone but you have to give us something to work with. At least show us what the only one grain spreads worth of targets looks like.

It was a starting point! The 0.1gr increments were already recommended and yeah that I will work on next...

 

[smoothy8500]

maybe your aren't the SME I'm looking for....

Oh, dear.....I think he's figured us out.

 

[DAMNKID]

I think what he’s getting at is that’s not a stable load If a change of 2 tenth gives you that much poi shift,not a good starting point. Your better off looking for loads that has very similar POI with different charge weights then you can tune them in with seating depth change. That’s why he's asking what the other targets looks like.

 

[Precision Underground]

Go and read exactly how to do an OCW test. Follow it exactly. You’re not looking for a good group. You’re looking for similar poi between charge weights. That’s why ppl were busting your balls. Posting two groups from a load test makes it impossible to draw a conclusion. Make sure you’re shooting them round-robin. If you’re not sure if the deviation is you or the load, RR will help prevent false results due to error induced by you.

If you’re not pretty confident that you can shoot 5-7 round robin groups without inducing error(it’s not easy to do), I’d pick a known good/mild load and load 50 or so and go practice a couple of times a week before chasing a load.

 

[spife7980]

It was a starting point! The 0.1gr increments were already recommended and yeah that I will work on next...

Thats not even what I was saying. Share your prior work, not just the smallest possible subsection of it that you could manage.

 

[Sniper1*]

Oh, dear.....I think he's figured us out.

I mostly have positive experiences here and watch many others get flamed by some members and it always turns a guy off from asking questions. Not everyone is an expert on here which is why they might think they can come and ask an expert. But with responses with no information that can be used other than “go back to the drawing board”, [your shooting sucks basically, or “not enough information provided” I can see why someone would be turned off.

I came looking for advice and started getting blasted from the beginning rather than starting a mutual conversation.

 

[Sniper1*]

Thats not even what I was saying. Share your prior work, not just the smallest possible subsection of it that you could manage.

Roger that! When I can get back in front of a computer to type I will.

 

[Sniper1*]

Go and read exactly how to do an OCW test. Follow it exactly. You’re not looking for a good group. You’re looking for similar poi between charge weights. That’s why ppl were busting your balls. Posting two groups from a load test makes it impossible to draw a conclusion. Make sure you’re shooting them round-robin. If you’re not sure if the deviation is you or the load, RR will help prevent false results due to error induced by you.

If you’re not pretty confident that you can shoot 5-7 round robin groups without inducing error(it’s not easy to do), I’d pick a known good/mild load and load 50 or so and go practice a couple of times a week before chasing a load.

Thank you! I’ll take a solid look!

 

[Sniper1*]

I think what he’s getting at is that’s not a stable load If a change of 2 tenth gives you that much poi shift,not a good starting point. Your better off looking for loads that has very similar POI with different charge weights then you can tune them in with seating depth change. That’s why he's asking what the other targets looks like.

Gotcha! I’ll put a more detailed report together.

 

[TX_Diver]

How much do you shoot? What do you want to do with the rifle/load? Those groups probably don't give you much reliable data unless you reshoot them again and again and get consistent results. All of them overlaid give you like 1.5" or so assuming those are 1" squares?

Unless you shoot a lot already and don't need to work on positions, etc. you could probably pick almost any of them and be better off spending more time shooting. If you just want to shoot steel at a few hundred yards most of them would probably work fine?

 

[Sniper1*]

How much do you shoot? What do you want to do with the rifle/load? Those groups probably don't give you much reliable data unless you reshoot them again and again and get consistent results. All of them overlaid give you like 1.5" or so assuming those are 1" squares?

Unless you shoot a lot already and don't need to work on positions, etc. you could probably pick almost any of them and be better off spending more time shooting. If you just want to shoot steel at a few hundred yards most of them would probably work fine?

I’m working up a load mostly for Coyote hunting and then some LR fun as well. I shoot most weeks throughout the summer months out to 1200 but have been using my 300wm (elk hunt prepping).

Not gonna try to convince anyone, especially on here, about my skill set, but I know how to shoot, and I know how to shoot at distance from alternate positions. I’m not looking to build a round for practice or competition.

 

[Jack's Dad]

Take the third group and don't pull the third shot next time. Don't over think it.

 

[Sniper1*]

Take the third group and don't pull the third shot next time. Don't over think it.

Roger!

 

[2aBaC̶a̶]

sample size of 3 is not enoughbto deduce any statistical significance. if your looking for bes groups I would say 5 shots, for data numbers 10+.

Im getting lazy and components are to scarce to run a bunch of tests. I just load a single shot ladder to find speeds and where pressure signs show up then just pick a speed and load a bunch.

ES and SD is a reflection of your loading precision. SD of 10 and ES of 30 is more than adequate for most shooting.

Accuracy is a reflection of you and your gun. if you have to tweak a load to find an accurate load it might not be the load.

Ive had high ES/SD loads group amazing and low ES/SD loads not. ‍♂

imo, dont waste a bunch of time amd money chasing the perfect load.

 

[Sniper1*]

sample size of 3 is not enoughbto deduce any statistical significance. if your looking for bes groups I would say 5 shots, for data numbers 10+.

Im getting lazy and components are to scarce to run a bunch of tests. I just load a single shot ladder to find speeds and where pressure signs show up then just pick a speed and load a bunch.

ES and SD is a reflection of your loading precision. SD of 10 and ES of 30 is more than adequate for most shooting.

Accuracy is a reflection of you and your gun. if you have to tweak a load to find an accurate load it might not be the load.

Ive had high ES/SD loads group amazing and low ES/SD loads not. ‍♂

imo, dont waste a bunch of time amd money chasing the perfect load.

This is exactly why I I posted the minimal information in the first place…. Thank you for the reply. I am looking for opinions about what I posted from someone more qualified and intelligent than me. Thanks again….

 

[smoothy8500]

Just curious in the different poi with two close loads. Shot round-robin or one group, next group? Either way, 1/2 moa shift is an issue.

 

[Sniper1*]

Just curious in the different poi with two close loads. Shot round-robin or one group, next group? Either way, 1/2 moa shift is an issue.

They were shot one group! Didn’t think about shooting round-robin as to be quite honest, I can’t figure out how to add “shots” to a series on the LabRadar or if it’s even possible. So, I shot one group, changed targets and wrote down information and waited for the gun to cool at least a little bit and then shot the next 3…. I like the round-robin idea and then just do the math manually to get some numbers.

 

[2aBaC̶a̶]

They were shot one group! Didn’t think about shooting round-robin as to be quite honest, I can’t figure out how to add “shots” to a series on the LabRadar or if it’s even possible. So, I shot one group, changed targets and wrote down information and waited for the gun to cool at least a little bit and then shot the next 3…. I like the round-robin idea and then just do the math manually to get some numbers.

The round Robin thing is for POI shift and you don't really need the Labrador for that. If you're shooting to find the data ES and SD then you don't need a shoot round Robin. They're 2 different tests. if you want to keep track RR just get a notepad and write down velocites per target.

 

[Sniper1*]

The round Robin thing is for POI shift and you don't really need the Labrador for that. If you're shooting to find the data ES and SD then you don't need a shoot round Robin. They're 2 different tests. if you want to keep track RR just get a notepad and write down velocites per target.

Yep…. I’m starting to see the relevance here

 

[nn8734]

Yep…. I’m starting to see the relevance here

Dont worry about SD and ES initially. Here’s how i approach load dev and testing, perhaps this may help:

Step	What I'm Doing	What I'm Looking For	Notes
1	Initial OCW 3-5 shots per group	POI Consistency from Chg Weight to Chg Weight, MV and Pressure Signs	MV Data: Im only looking at MV (not SD or ES) to see what charge weights my min required MV is met and if pressure is present at that MV where POI is consistent from increment to increment
2	Refined OCW 10-15 shots per group, adjacent CWs	POI consistency (repeated from initial OCW), group size at 100m and at 600m	If group size is not to my liking but MV (speed) and POI consistency is there, I go to seating depth testing in an additional session before going to step 3
3	Final validation - 40-60 rounds	MV Consistency (SD/ES), group size, elevation hold overs at various KDs vs predicted (either via FDAC or ballistic app), overall performance impressions	If SD/ES are reasonable (low double digits, high single digits across 40 rounds im good - i put the load into production. If it all comes apart, i diagnose and re-group (honestly, this very rarely happens)

 

[Sniper1*]

Dont worry about SD and ES initially. Here’s how i approach load dev and testing, perhaps this may help:

Step	What I'm Doing	What I'm Looking For	Notes
1	Initial OCW 3-5 shots per group	POI Consistency from Chg Weight to Chg Weight, MV and Pressure Signs	MV Data: Im only looking at MV (not SD or ES) to see what charge weights my min required MV is met and if pressure is present at that MV where POI is consistent from increment to increment
2	Refined OCW 10-15 shots per group, adjacent CWs	POI consistency (repeated from initial OCW), group size at 100m and at 600m	If group size is not to my liking but MV (speed) and POI consistency is there, I go to seating depth testing in an additional session before going to step 3
3	Final validation - 40-60 rounds	MV Consistency (SD/ES), group size, elevation hold overs at various KDs vs predicted (either via FDAC or ballistic app), overall performance impressions	If SD/ES are reasonable (low double digits, high single digits across 40 rounds im good - i put the load into production. If it all comes apart, i diagnose and re-group (honestly, this very rarely happens)

That’s some good info. Thanks

 

[Thump_rrr]

They were shot one group! Didn’t think about shooting round-robin as to be quite honest, I can’t figure out how to add “shots” to a series on the LabRadar or if it’s even possible. So, I shot one group, changed targets and wrote down information and waited for the gun to cool at least a little bit and then shot the next 3…. I like the round-robin idea and then just do the math manually to get some numbers.

This is exactly why I sometimes hate using the LabRadar

 

[Thump_rrr]

Just to give you a little perspective.
I've never used any of the RL powders since I've never found any around here.
The first target was my original load development with the factory barrel on my Savage 12FV.
This target was shot on New Years Eve day 2020 Outdoor temperature was -5F

The second target was shot less than 3 weeks ago doing load development on my new IBI barrel. Temperature was in the low 30’s

For the 41.0gr H4350 MV was 2727, ES was 6.15 and SD was 3.11.
For the 41.3gr only 2 rounds recorded.
MV was 2745, ES was 3.96, and SD was 2.80

 

[CK1.0]

Remember: this OCW stuff isn't actually science, it's a "concept"... from a guy, on the internet, who has "a friend who is an engineer who has a plausable idea of why it might actually work" (from www.ocwreloading.com).

Pick a speed, find the bullet-jump range (seating depth) that groups best with your bullet/barrel combo: voila!

 

[Precision Underground]

Remember: this OCW stuff isn't actually science, it's a "concept"... from a guy, on the internet, who has "a friend who is an engineer who has a plausable idea of why it might actually work" (from www.ocwreloading.com).

Pick a speed, find the bullet-jump range (seating depth) that groups best with your bullet/barrel combo: voila!

I’ve done enough tests to be 100% convinced that it works but I’m not at all convinced that it works bc of bullet timing/exit. I doubt the science of minute changes in charge weight making a repeatable difference in bullet timing. The scale is too small for it to make sense.

I think it’s more about the frequency of the vibration in the barrel that is generated by different charge weights. If it’s in tune it’s uniform and predictable. If it’s not in tune it’s chaotic and unpredictable. The thinner the barrel the more sensitive it’s going to be to changes in charge weight/frequency. This is why the truck axle 6mm barrel guys say charge weight doesn’t matter. Because they’re right, it really doesn't matter much with a thick barreled 6mm. Those barrels are going to resonate at a much more uniform frequency no matter the charge weight.

That’s all theory of course but it makes way more sense to me than saying you’re consistently controlling bullet exit on a millisecond scale by changing charge weight by .2gr.

 

[Baron23]

They were shot one group! Didn’t think about shooting round-robin as to be quite honest, I can’t figure out how to add “shots” to a series on the LabRadar or if it’s even possible. So, I shot one group, changed targets and wrote down information and waited for the gun to cool at least a little bit and then shot the next 3…. I like the round-robin idea and then just do the math manually to get some numbers.

Nah, can’t go back into a series on the Labradar. I know exactly what you are saying and nope, can’t.

And…you do have a thick skin and have stayed pretty cheerful.

 

[whatsupdoc]

Little test I did years ago with a B14 HMR in 6.5 creed at 200 yards.
Dot is 1 inch, group is about 1/2 inch. It seems the charge variation did not affect the group as much
as you would think.

You need to confirm the neck bushing sizes, I use a .288 die for Lapua brass but for Hornady I use a .286
bushing. Are you using the expander on the die or a mandrel to expand the neck.

Your ES are high and most likely a case prep issue.

 

[CK1.0]

I’ve done enough tests to be 100% convinced that it works but I’m not at all convinced that it works bc of bullet timing/exit. I doubt the science of minute changes in charge weight making a repeatable difference in bullet timing. The scale is too small for it to make sense.

I think it’s more about the frequency of the vibration in the barrel that is generated by different charge weights. If it’s in tune it’s uniform and predictable. If it’s not in tune it’s chaotic and unpredictable. The thinner the barrel the more sensitive it’s going to be to changes in charge weight/frequency. This is why the truck axle 6mm barrel guys say charge weight doesn’t matter. Because they’re right, it really doesn't matter much with a thick barreled 6mm. Those barrels are going to resonate at a much more uniform frequency no matter the charge weight.

That’s all theory of course but it makes way more sense to me than saying you’re consistently controlling bullet exit on a millisecond scale by changing charge weight by .2gr.

The thing is, are you sure you're 100% convinced it works because it works... or maybe because "that's the way we've always done it" (bubba syndrome) or because you've "done enough tests" (performed the same ritual over and over while believing there's substance to it when there isn't), and thus preprogrammed yourself to be biased towards seeing a correlation in the result that jives with what you were already looking for?

It's a Rorschach test, guys will see what they want to see.

Many rifle "reloading concepts" are premised on some sort of frequency/harmonic/resonance correlation between combustion and the projectile exiting the barrel at a favorable moment (bang, sine waves, bullet exit). But some things, like seating depth and tuners, for example, are based in real science (chasing the sine wave), whereas the "magic optimal charge weight" concept is about the most coarse way to go about accomplishing something like that, rooted more in coincidence and luck than anything else. A broken watch is right twice a day too.

I mean, that's just like my opinion, man.

 

[straightshooter1]

I’ve done enough tests to be 100% convinced that it works but I’m not at all convinced that it works bc of bullet timing/exit. I doubt the science of minute changes in charge weight making a repeatable difference in bullet timing. The scale is too small for it to make sense.

I think it’s more about the frequency of the vibration in the barrel that is generated by different charge weights. If it’s in tune it’s uniform and predictable. If it’s not in tune it’s chaotic and unpredictable. The thinner the barrel the more sensitive it’s going to be to changes in charge weight/frequency. This is why the truck axle 6mm barrel guys say charge weight doesn’t matter. Because they’re right, it really doesn't matter much with a thick barreled 6mm. Those barrels are going to resonate at a much more uniform frequency no matter the charge weight.

That’s all theory of course but it makes way more sense to me than saying you’re consistently controlling bullet exit on a millisecond scale by changing charge weight by .2gr.

Hmmm??? Looks to me like you've got some of it right and some of it wrong.

Yes, though barrel time is measured in milliseconds, the timing of the exit has to be at the right time of the anti-node of the barrel's frequency. While the frequency of the barrel is constant, the speed (in milliseconds is not due to various things effecting the speed of the projectile. The trick is to minimize those variation and make the speed of the projectile consistent enough to work effectively in that part of the antinode that produces consistent timing of the release. If the projectile is not released at the antinode, then the small variation in barrel time will result in significant variations in POI's.

Heavy "truck axle" barrels will have a much lower frequency than a thinner barrels and that lower frequency will have a larger period of time in the antinode for the variations in barrel time to work well. That's why heavy barrels are known to have a much wider harmonic node for precision than thinner barrels.

Another aspect I've noticed is the amplitude of the frequency can effect how wide the harmonic node for precision is. The higher the amplitude, the shorter the time available in the antinode for a consistent projectile release. You get higher amplitudes from a barrel using hot loads than with mild loads.

Many things effects barrel-time/exit besides charge weights; like seating depth, primer ignition of the powder, the neck releasing the projectile, etc. The barrel harmonic frequencies move down the barrel extremely fast and can also be measured in milliseconds. So, it's all about timing.

BTW, have you ever tried striking different barrels with a rubber mallet, like one might do with a tuning fork, like a tuning fork, you can actually hear the different frequencies of the barrels?

 

[Bacarrat]

Everyone has a different way to interpret loads and how it should go. IMO with the .2 difference in charge, your ES and SD are all over the board. Might need to test more rounds to get a better sample size. You have one really good load with the 2 loads that are 10+ on the SD, I'm thinking brass or brass prep that can lead to that.. To, me that's not a lot of room to play with. Knowing how RL16 shoots, you might be able to go a little hotter and still be safe. Normally, I would want a couple of powder charges in a row to be around the same ES and SD. Then work your seating depths from there.

 

[CK1.0]

Ok, I need to have better manners, it's not nice to piss on anyone's OCW party. If that's what one likes to do, do it.

Just know that none of this optimal charge weight and node shit makes any sense... but then, either does sticking "Glock" and "Sig" stickers on one's truck unless they want someone to break into it... and lots of gun guys still haven't figured that out either.

 

[Precision Underground]

The thing is, are you sure you're 100% convinced it works because it works... or maybe because "that's the way we've always done it" (bubba syndrome) or because you've "done enough tests" (performed the same ritual over and over while believing there's substance to it when there isn't), and thus preprogrammed yourself to be biased towards seeing a correlation in the result that jives with what you were already looking for?

It's a Rorschach test, guys will see what they want to see.

Many rifle "reloading concepts" are premised on some sort of frequency/harmonic/resonance correlation between combustion and the projectile exiting the barrel at a favorable moment (bang, sine waves, bullet exit). But some things, like seating depth and tuners, for example, are based in real science (chasing the sine wave), whereas the "magic optimal charge weight" concept is about the most coarse way to go about accomplishing something like that, rooted more in coincidence and luck than anything else. A broken watch is right twice a day too.

I mean, that's just like my opinion, man.

Lol. It’s funny when guys call OCW tests and harmonics folklore in one sentence and then say that their tuner is based in science in the next sentence. Why do you think your tuner works? All a tuner does is change the way the barrel reacts to the explosion inside the rifle. Are you saying changing the size of the explosion won’t affect how the barrel reacts to it?

 

[straightshooter1]

Just know that none of this optimal charge weight and node shit makes any sense...

 

[Sniper1*]

Little test I did years ago with a B14 HMR in 6.5 creed at 200 yards.
Dot is 1 inch, group is about 1/2 inch. It seems the charge variation did not affect the group as much
as you would think.

You need to confirm the neck bushing sizes, I use a .288 die for Lapua brass but for Hornady I use a .286
bushing. Are you using the expander on the die or a mandrel to expand the neck.

Your ES are high and most likely a case prep issue.

View attachment 8005979

Thanks for the response. I’ve measured a few times and I get 0.015” neck thickness every time. If I run a .288 bushing with no expander my case mouth is .260” consistently.

Now here is the part I might have wrong! I don’t use an expander at all. Every case is once fired (so far) in this gun. The case mouth is already large enough for the new bullet to slip into freely. I watched the Hornady Video on Matchmaster Die setup and the guy removed the expander ball and said to replace it with the plain de-capper pin retainer which does no sizing.

I have never used a neck bushing die and use a 21st Century Mandrel for my 300wm after full-length sizing with a Redding Comp Die.

 

[ma smith]

OP you probably need an expander or mandrel in your process with 4 thou neck tension

Read Brian Litz Vol 3 on sample size / load deve and tuner testing to understand how much of this is stochastic noise.

 

[Sniper1*]

OP you probably need an expander or mandrel in your process with 4 thou neck tension

Read Brian Litz Vol 3 on sample size / load deve and tuner testing to understand how much of this is stochastic noise.

It seemed odd to not have the expander ball. I watched the video a few times and my take away was the same each time - remove the expander

It’s too easy to get caught up in all the “white noise”.

ETA - after some more research it seems there are two schools of thought on the neck bushing/expander ball issue.

Camp 1 - in summary, neck bushing no expander or mandrel, the extra work hardens brass, it isn’t necessary because the bullet will make it round, it can cause changes in shoulder bump, brass length, etc…

Camp 2 - also in summary, neck bushing with expander ball or mandrel is necessary because it will create a round case mouth and remove imperfections and create uniformity in the neck.

 

[ma smith]

OP, can you see Your POI is shifting, and inconsistent with MV direction?

I'm seeing .5 to .7MOA shift opposite the direction of MV change.
This is a red flag, likely something unexplained is going on.

In general the FPS up should not lead to POI down.

 

[Sniper1*]

OP, can you see Your POI is shifting, and inconsistent with MV direction?

I'm seeing .5 to .7MOA shift opposite the direction of MV change.
This is a red flag, likely something unexplained is going on.

In general the FPS up should not lead to POI down.

Yep I see that shift as well. Not experienced enough to know why.

Maybe I’ll run another test set and use the expander ball installed.

Oh and BTW Happy Thanksgiving to you and everyone else that sees this today.

 

[2aBaC̶a̶]

The real difference between bushing only and expander is that bushing makes the outside of the case neck uniform. The expander or mandrels make the inside uniform where it matters. if there are irregularity or varying case thicknesses you want the difference pushed to the outside and not effecting neck tension. if you really want to see this get some individual pin guages from amazon. you'll be surprised on the variances. some will slide in and some will not. some ill send through the mandrel a second time.

keep an eye on the inside of the case necks. I had problems with the hornady expander galling and scratching the inside of the case mouth. I ended up polishing it down so that it only straightens dented case. then a separate carbide or Ti mandrel does the actual work with no galling.

On your next target you might try just using a blank target draw a horizontal line and put some small dots on it a few inches apart. having them all lined up helps visualize the poi shift.