Lot Testing With Tuner

G

Gjmen22

New member
I have recently purchased a Harrell tuner and found my sweet spot of #479. I used the Hopewell Method and it went pretty smooth. My question is, soon I will need more ammo so the process of lot testing will begin. How is this done wit the tuner? Do I leave the setting where its at? Will I be close? Is the tuner good at #479 for all ammo? Or do I pull off the tuner, find the best lot and then do the tuner adjustment all over again?

Thank you,
Gjmen22
 
Gjmen22 said:
I have recently purchased a Harrell tuner and found my sweet spot of #479. I used the Hopewell Method and it went pretty smooth. My question is, soon I will need more ammo so the process of lot testing will begin. How is this done wit the tuner? Do I leave the setting where its at? Will I be close? Is the tuner good at #479 for all ammo? Or do I pull off the tuner, find the best lot and then do the tuner adjustment all over again?

Thank you,
Gjmen22
Click to expand...

Lots of opinions on this and Calfee is probably responsible for the "never move it" theory.

My experiences differ from his and if you are the type that believes art comes before physics, you'll likely agree with him.

IME, there is no possible reason why a barrel would have some magical position where it is miraculously in some sort of mythical "harmony"...where it will shoot any velocity equally well. That's just a physical impossibility.

Powder burning is a chemical reaction...all chemical reactions are temerature dependent. So, even as temps change, perfect tune also WILL change. Changing ammo in a rf is no different at all than changing the load in a centerfire rifle. CF shooters have traditionally changed loads to keep up with changing conditions.

Both cf and rf are made of a hunk of steel and a stock. You must ask yourself what makes a factory loaded rf cartridge different than a handloaded cf cartridge and why they would behave differently.

The bottom line question is, do you put more faith in physics or art.

With even premium rf ammo being what it is, it doesn't hold a candle to cf rifles and ammo. So, there must be at least some little piece of art that makes them shoot well, when they do. ;).

With cf, very little about tuning is left to doubt. Why the difference?
 
Last edited:
mwezell said:
Lots of opinions on this and Calfee is probably responsible for the "never move it" theory.

My experiences differ from his and if you are the type that believes art comes before physics, you'll likely agree with him.

IME, there is no possible reason why a barrel would have some magical position where it is miraculously in some sort of mythical "harmony"...where it will shoot any velocity equally well. That's just a physical impossibility.

Powder burning is a chemical reaction...all chemical reactions are temerature dependent. So, even as temps change, perfect tune also WILL change. Changing ammo in a rf is no different at all than changing the load in a centerfire rifle. CF shooters have traditionally changed loads to keep up with changing conditions.

Both cf and rf are made of a hunk of steel and a stock. You must ask yourself what makes a factory loaded rf cartridge different than a handloaded cf cartridge and why they would behave differently.

The bottom line question is, do you put more faith in physics or art.

With even premium rf ammo being what it is, it doesn't hold a candle to cf rifles and ammo. So, there must be at least some little piece of art that makes them shoot well, when they do. ;).

With cf, very little about tuning is left to doubt. Why the difference?
Click to expand...

Mike:

Great post, I couldn't agree more.

I do think that there are some sweet spots that are wider (or at least more tolerant) of velocity changes than others, but I fully agree that "tune" is velocity dependent - and subject to the variables you mentioned.

When I am developing tuner settings for a season, I like to run two independent tests with two lots of differing velocities - just to see if there is any overlap or common tuner positions. Personally, I find these settings as I mentioned more tolerant than others. It may be a compromise though - but it seems to avoid some of the sensitivity of other settings.

All the best to you,

kev
 
Tuning

Gjmen22, If your getting more ammo of the same brand that you tuned for but a different lot#,
leave the tuner on and “warm up the gun”.
When your ready, shoot a few three shot groups, if the groups look too big move your tuner
in small increments and see how the grouping changes.
With any luck, testing the same brand but different lot#, you should be pretty close.
If you plan to test a different brand of ammo at a higher or lower velocity,
use the same method and keep accurate notes as to what you have done.

Bob
 
kevinnevius said:
Mike:

Great post, I couldn't agree more.

I do think that there are some sweet spots that are wider (or at least more tolerant) of velocity changes than others, but I fully agree that "tune" is velocity dependent - and subject to the variables you mentioned.

When I am developing tuner settings for a season, I like to run two independent tests with two lots of differing velocities - just to see if there is any overlap or common tuner positions. Personally, I find these settings as I mentioned more tolerant than others. It may be a compromise though - but it seems to avoid some of the sensitivity of other settings.

All the best to you,

kev
Click to expand...


Thanks Kevin and all the best to you as well...

There are days that I never touch the tuner and there are days that I do, but I always move methodically and in very small increments.
Temp is the biggest variable but not the only factor, as there must be an offsetting factor as well, hence the same temp change doesn't automatically require a corresponding tuner change. I won't get into theories here but I suspect it has a lot to do with what you are seeing, as does having the bullet exit at the top of the barrel swing.
 
Thank you for all the good info gentlemen. I appreciate the comments. Now, lets just hope I can find that magical lot that was dusted with unicorn dandruff. :)
 
kevinnevius said:
Mike:

When I am developing tuner settings for a season, I like to run two independent tests with two lots of differing velocities - just to see if there is any overlap or common tuner positions.
Click to expand...

Mr Nevius,

When you are developing tuner settings with ammo lots, do you shoot from position with a sling, from a rest or with the rifle in a vice/machine rest ?

Paul
 
Paul said:
Mr Nevius,

When you are developing tuner settings with ammo lots, do you shoot from position with a sling, from a rest or with the rifle in a vice/machine rest ?

Paul
Click to expand...

Good morning Paul:

From a rest, in controlled conditions (I have access to an indoor 50 meter facility near my home).

After I establish preliminary sweet spot position(s), I verify them in position (but I rarely change them). There have been times that defined sweet spots from the bench have not translated to position testing - which (to me, at least) makes sense. There are so many variables between the two regarding the transmission of recoil and general load placement on the stock to name a few. But most of the time, things work out and the system shoots well in position as optimized from the bench.

I am not the best bench shooter on the planet (no surprise there! LOL), but it is really the only way to try to eliminate as much of the shooter error as possible, while maintaining some similarities to the rifle shot in position.

I know this wasn't a part of your question, but I have been asked about the translation of test center results (any of them) to accuracy in actual use. IMHO, I think the facilities we have access to are absolutely invaluable and amazing, but I am not sure how much the group sizes mean outside of lot selection in those conditions with the barreled action fixed to a rigid base (I can only speak to prone shooting - the results may translate to BR use far better). Typically, I find selected lots actually perform better than expected when the rifles are assembled and used as intended.

I hope you are well, all the very best,

kev
 
With rimfire ammo I have found that the top brands are usually very consistent regarding powder charge, projectile weight and case dimensions.

I have noticed small variations in overall length which might affect accuracy due to slight variations in 'jump'.

Only a few thou but it does make a difference, that's why I made a sizing gauge which seems to be useful.

Some manufacturers publish tables of lot numbers such as this https://eley.co.uk/find-the-perfect-batch-with-eleys-lot-analyser/.

While useful, they were not produced using your barrel so take them as a guide only to the consistency of the batch.

* doggie *
 
Ely Analyzer

Is no longer accessible, I liked it to pick test lots, didn't have to do as many test lots to find
one wanted to go with.
 
Need some info

kevinnevius said:
good morning paul:

From a rest, in controlled conditions (i have access to an indoor 50 meter facility near my home).

After i establish preliminary sweet spot position(s), i verify them in position (but i rarely change them). There have been times that defined sweet spots from the bench have not translated to position testing - which (to me, at least) makes sense. There are so many variables between the two regarding the transmission of recoil and general load placement on the stock to name a few. But most of the time, things work out and the system shoots well in position as optimized from the bench.

I am not the best bench shooter on the planet (no surprise there! Lol), but it is really the only way to try to eliminate as much of the shooter error as possible, while maintaining some similarities to the rifle shot in position.

I know this wasn't a part of your question, but i have been asked about the translation of test center results (any of them) to accuracy in actual use. Imho, i think the facilities we have access to are absolutely invaluable and amazing, but i am not sure how much the group sizes mean outside of lot selection in those conditions with the barreled action fixed to a rigid base (i can only speak to prone shooting - the results may translate to br use far better). Typically, i find selected lots actually perform better than expected when the rifles are assembled and used as intended.

I hope you are well, all the very best,

kev
Click to expand...
have 1 250 bbl does tunner help this heavy bbl i put it on unml rail bill brawand hope for ans
 
QUOTE:”have 1 250 bbl does tunner help this heavy bbl i put it on unml rail bill brawand hope for ans “

Hey Bill, I have not seen a tuner on a 1.25” bbl rail gun.
I’m not saying they don’t exist, just that I have never seen one.
Just out of curiosity though; Is that rail a rimfire?

Bob
 
bob1949 said:
quote:”have 1 250 bbl does tunner help this heavy bbl i put it on unml rail bill brawand hope for ans “

hey bill, i have not seen a tuner on a 1.25” bbl rail gun.
I’m not saying they don’t exist, just that i have never seen one.
Just out of curiosity though; is that rail a rimfire?

Bob
Click to expand...
my old unl i put rimfire bbl on it but i have seen a no. Of centfire with turners
 
Great barrel Billy. I doubt a tuner will do much but you never know, the hard part is figuring out how to fit one on that pipe.:D
 
tim said:
great barrel billy. I doubt a tuner will do much but you never know, the hard part is figuring out how to fit one on that pipe.:d
Click to expand...
it was a clamp on type a fellow throwed on my table at ny.at a centerfire match so i chambered up 4 new rimfire bbls to fit clamp on tuner to see what acc/. I can get when i get better weather just checking to see if it would be commp. I was told big rimfire bbls have no vivs so turner doesnt help. Fellows out there let me know. Thanks bill.
 
BillBrawand said:
it was a clamp on type a fellow throwed on my table at ny.at a centerfire match so i chambered up 4 new rimfire bbls to fit clamp on tuner to see what acc/. I can get when i get better weather just checking to see if it would be commp. I was told big rimfire bbls have no vivs so turner doesnt help. Fellows out there let me know. Thanks bill.
Click to expand...

Well they certainly do but it seems they are a different animal entirely and seem harder to tune, tell us what you find if you fit it up.
It seems the sweet spot for a "tunable" barrel in terms of getting results within a reasonable effort is thought to be in the .875"-.900" range with .900" or so being the most popular.
 
Gjmen22 said:
I have recently purchased a Harrell tuner and found my sweet spot of #479. I used the Hopewell Method and it went pretty smooth. My question is, soon I will need more ammo so the process of lot testing will begin. How is this done wit the tuner? Do I leave the setting where its at? Will I be close? Is the tuner good at #479 for all ammo? Or do I pull off the tuner, find the best lot and then do the tuner adjustment all over again?

Thank you,
Gjmen22
Click to expand...

Adjusting a new tuner with several lots/brands of ammo is not real complicated since several hundred shots on a rf doesn’t hurt barrel life where several hundred rounds on a cf can shoot it out.

Adjust the new tuner with an ammo lot you have plenty of. Then at that fixed setting pick the best lot/brand. Then with that best lot/brand go back and readjust the new tuner.


.
 
BillBrawand said:
have 1 250 bbl does tunner help this heavy bbl i put it on unml rail bill brawand hope for ans
Click to expand...

Hi Bill:

I appreciate the question, thanks for the post!

I have no experience with unlimited rail guns (besides shooting a few at Kelbly's!), and no experience with a RF barrel that large. It makes sense to me though that the ability to adjust the position of mass would be beneficial - I just have no experience telling you how much.

Please keep us informed - always interested in other applications.

All the best,

kev
 
bob1949 said:
quote:”have 1 250 bbl does tunner help this heavy bbl i put it on unml rail bill brawand hope for ans “

hey bill, i have not seen a tuner on a 1.25” bbl rail gun.
I’m not saying they don’t exist, just that i have never seen one.
Just out of curiosity though; is that rail a rimfire?

Bob
Click to expand...
both cf rf

Code:
 
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