Testing smallbore ammo lots: tuner tube on or off?

[Hi-NV Shooter]

Tim, I first want to thank you for your long reply. We can agree to some things but some we will not and that's fine. My biggest point on this is that set and forget is not the only way. Don't get me wrong there has been a lot of fine shooting and records done with that mindset, but there are a bunch of top guys twisting and winning big, and setting new records in the last few years as well. I think that adjusting while shooting, when necessary, is the better option even though it may be initially a bit harder to get a handle on. I think the ammo situation now only furthers the need to adjust and keep up with the ammo but there are benefits even realized when ammo was how it used to be.

We have not had the opportunity to work with either of the LT's but know they are very good powders. Did you preload with it before match day?



Now for the quoted section above, I have the same thoughts for shooters not willing to learn what it takes to keep a gun in tune and stay on set and forget. Our equipment may be equal at their best, but when the set and forget guy "can't make anything work", I have a way to adjust to make it happen. I have witnessed that one for years as well. Do not underestimate the guys that are willing to actually learn the adjust when needed side. The mindless twisters that do not know where they are going or why with an adjustment I actually have empathy for. They recognize there is some sort of issue or problem and at least they are trying something to improve things and their chances of doing better.

Tad

Tad, how do you conclude when your rifle is out of tune? what is it that brings you to that conclusion. is it based on shooting the same lot and it is just not going where you think it should when previous outings it shot lights out?
I am in the group of set and forget. and I admit it wasn't an easy path to get there took a lot of testing with all components involved. if for some reason my rifles are not shooting how they have been it is always something to do with the rest/recoil management a quick adjustment on the front bag and it will go back to how it should shoot. took me awhile to understand this. I guess that is one of quirks of using a sandbag top and different stocks.
just wondering how you decide when something is out of sync.

Lee

 

[CharlieNC]

Don’t know….don’t care. I do know what works.
While no major WLM fan, zero argument about what he,’s built and who shoots them, same exact approach with Eck. I also happened to be a close friend of Chet Amick, talked to him couple times a week for years before his passing, lots of exchanges about tuning….same exact approach, these guys have virtually zero in common other than excellent result.
Countless guns and winners over many years…..SAME EXACT TUNING APPROACH.
Now at the risk of being rude Mike but the sum total of guns and tunes you are responsible for equals approximately zero percent of that population.
Now I truly love to know why something works but aI fully except that , more important is the realization of what does work. Me…I’m more than comfortable with the approach myself and that esteemed body have developed and this will no doubt be litigated until we’re both long gone. You’re gonna believe what you’re gonna believe but I’ll stand my track record over many years as personal proof of concept.
I should be happy you send so many guys down that dirt road…..love to shoot against them.
I would truly love to know the % of diehard tuner twisters consist of guys simply unable to admit they are notcas good as they think and/or simply missed conditions, always blame ammo, etc., been witnessing them for years.

Can you provide details of this tuning approach?

 

[VLNBYR]

If you are going to decide something isn't right shouldn't it involve the same amount of time and effort you put into deciding it was right?????

 

[gunsandgunsmithing]

Don’t know….don’t care. I do know what works.
While no major WLM fan, zero argument about what he,’s built and who shoots them, same exact approach with Eck. I also happened to be a close friend of Chet Amick, talked to him couple times a week for years before his passing, lots of exchanges about tuning….same exact approach, these guys have virtually zero in common other than excellent result.
Countless guns and winners over many years…..SAME EXACT TUNING APPROACH.
Now at the risk of being rude Mike but the sum total of guns and tunes you are responsible for equals approximately zero percent of that population.
Now I truly love to know why something works but aI fully except that , more important is the realization of what does work. Me…I’m more than comfortable with the approach myself and that esteemed body have developed and this will no doubt be litigated until we’re both long gone. You’re gonna believe what you’re gonna believe but I’ll stand my track record over many years as personal proof of concept.
I should be happy you send so many guys down that dirt road…..love to shoot against them.
I would truly love to know the % of diehard tuner twisters consist of guys simply unable to admit they are notcas good as they think and/or simply missed conditions, always blame ammo, etc., been witnessing them for years.

I was really just hoping you or anyone could help me learn how there is one spot on a tuner that shoots everything, all the time, to its full potential. I'm still looking for that, not any pee'ing matches...just solid info that makes any sense, physically. Thanks for your reply.

 

[Ccrider]

First, this is a great thread with valuable input from some of the best shooters around. Thanks for sharing.

Seems like some of you guys are talking rimfire/tuner use while others are conflating the discussion with centerfire tuner use.

No one has directly addressed whether weather, bp, humidity etc., impact Rimfire tune. If they do, can the impact be negated by tuner adjustments?

 

[Tad_Earhart]

Lee,
You bring up some great points on the rest affecting the overall tune of the rifle with its relationship to recoil management. The sand bag tops are not a bad option all things considered but are prone to issues like you point out. Matter of fact that is what we settled on prior to where we are at now. Now, we use rollers front and rear to create as much consistency and free movement as possible, with the rifle recoil restricted by my return device. It is HUGE to tune to keep recoil movement consistent at a certain rate as you already know. The same stuff can be achieved with even two piece rest setups, it is just more time consuming to get there. If a person is trying to shoot multiple rifles out of one rest setup there is also more work that needs to be done to figure out common ground or specific repeatable settings to the rifle and rest relationships. Can be done successfully, just needs more work to get there.

On deciding if the rifle is in tune or not, there are a couple of things we look at to determine. First, and maybe the easiest thing to see, is when you start to shoot your first card or warm up for the day, and immediately notice that the POI is low of POA. We base tune our rifles and establish scope zero for shooting at the top of the wave, so if there is a big (4-6 scope clicks) difference in POI/POA to the low side we know something is off in tune, and we are to one side or the other of the tune wave. Usually temp change since last time the rifle was shot will determine which direction to adjust from there in 1-2 click increments. Change will happen quickly for our setup once adjustments are made.

The next few things are harder to detect but easily seen if you know your rifle and done the work with it. Vertical stringing not related to wind (sometimes difficult to determine), and overall loose shooting with known quality lots are signs as well. A person needs to know their rifle well enough to determine if these are tune related or condition related things. Again never adjusting more than 1-2 clicks at a time without tracking the changes on target for our setup. The most I have ever adjusted during a match was 6 clicks from base tune, and that was on a day that seen a 37 degree temp change from start to finish of the match. There have also been days that no adjustment was needed. It is not dead set that adjustments have to be made all day every match but more times than not, there will need to be a click or two change made some time during the day. This is where knowing your stuff is so key to the deal and then having learned how to respond to changes when needed. It takes time and dedication to learning it but pays off when you need it.

Another key point to make here is that none of this is possible without very consistent ignition. That is a can of worms for another time.

 

[gunsandgunsmithing]

Tim, I first want to thank you for your long reply. We can agree to some things but some we will not and that's fine. My biggest point on this is that set and forget is not the only way. Don't get me wrong there has been a lot of fine shooting and records done with that mindset, but there are a bunch of top guys twisting and winning big, and setting new records in the last few years as well. I think that adjusting while shooting, when necessary, is the better option even though it may be initially a bit harder to get a handle on. I think the ammo situation now only furthers the need to adjust and keep up with the ammo but there are benefits even realized when ammo was how it used to be.

We have not had the opportunity to work with either of the LT's but know they are very good powders. Did you preload with it before match day?



Now for the quoted section above, I have the same thoughts for shooters not willing to learn what it takes to keep a gun in tune and stay on set and forget. Our equipment may be equal at their best, but when the set and forget guy "can't make anything work", I have a way to adjust to make it happen. I have witnessed that one for years as well. Do not underestimate the guys that are willing to actually learn the adjust when needed side. The mindless twisters that do not know where they are going or why with an adjustment I actually have empathy for. They recognize there is some sort of issue or problem and at least they are trying something to improve things and their chances of doing better.

Tad

Well said Tad. I agree with everything you said, fwiw. Also, I think if someone doesn't know how and when to adjust a tuner, they're likely better off leaving it alone. It's a tool, not a crutch.

Here's a thread I posted a few years ago that well represents why I use tuners. I've done essentially the same thing with both rf ancf as well as when changing ammo lots...fwiw, too. I feel very much like once you get comfortable properly adjusting a tuner...any tuner for the most part, that it becomes almost instinctive and a simple process that can be done very effectively and fast.

Tuner story...

I posted this story on another site but thought others may find it interesting and am posting here, too. The story is based on a rifle I bought last year, which had another maker's tuner on it when I got it. This tuner uses a slightly smaller thread diameter than mine, so rather than cutting an...

forum.accurateshooter.com

 

[gunsandgunsmithing]

Lee,
You bring up some great points on the rest affecting the overall tune of the rifle with its relationship to recoil management. The sand bag tops are not a bad option all things considered but are prone to issues like you point out. Matter of fact that is what we settled on prior to where we are at now. Now, we use rollers front and rear to create as much consistency and free movement as possible, with the rifle recoil restricted by my return device. It is HUGE to tune to keep recoil movement consistent at a certain rate as you already know. The same stuff can be achieved with even two piece rest setups, it is just more time consuming to get there. If a person is trying to shoot multiple rifles out of one rest setup there is also more work that needs to be done to figure out common ground or specific repeatable settings to the rifle and rest relationships. Can be done successfully, just needs more work to get there.

On deciding if the rifle is in tune or not, there are a couple of things we look at to determine. First, and maybe the easiest thing to see, is when you start to shoot your first card or warm up for the day, and immediately notice that the POI is low of POA. We base tune our rifles and establish scope zero for shooting at the top of the wave, so if there is a big (4-6 scope clicks) difference in POI/POA to the low side we know something is off in tune, and we are to one side or the other of the tune wave. Usually temp change since last time the rifle was shot will determine which direction to adjust from there in 1-2 click increments. Change will happen quickly for our setup once adjustments are made.

The next few things are harder to detect but easily seen if you know your rifle and done the work with it. Vertical stringing not related to wind (sometimes difficult to determine), and overall loose shooting with known quality lots are signs as well. A person needs to know their rifle well enough to determine if these are tune related or condition related things. Again never adjusting more than 1-2 clicks at a time without tracking the changes on target for our setup. The most I have ever adjusted during a match was 6 clicks from base tune, and that was on a day that seen a 37 degree temp change from start to finish of the match. There have also been days that no adjustment was needed. It is not dead set that adjustments have to be made all day every match but more times than not, there will need to be a click or two change made some time during the day. This is where knowing your stuff is so key to the deal and then having learned how to respond to changes when needed. It takes time and dedication to learning it but pays off when you need it.

Another key point to make here is that none of this is possible without very consistent ignition. That is a can of worms for another time.

More good stuff! I couldn't have said it better myself.

 

[JimSC]

I just have to wonder how many times the "set it and forget" crowd have gone to a match and found their rifles' preferred lot just wasn't shooting worth a darn. Then rather than move the tuner a click or two they futzed around with different lots losing points and places. Just something for thought.

I am not looking for a peeing contest either I also just want for someone to explain the physics behind why they believe barrel harmonics behave differently on a rimfire than a centerfire. I am willing to learn and change my opinions but I need something besides "that is what I was told" by someone to convince me

 

[TRSR8]

Tim, I first want to thank you for your long reply. We can agree to some things but some we will not and that's fine. My biggest point on this is that set and forget is not the only way. Don't get me wrong there has been a lot of fine shooting and records done with that mindset, but there are a bunch of top guys twisting and winning big, and setting new records in the last few years as well. I think that adjusting while shooting, when necessary, is the better option even though it may be initially a bit harder to get a handle on. I think the ammo situation now only furthers the need to adjust and keep up with the ammo but there are benefits even realized when ammo was how it used to be.

We have not had the opportunity to work with either of the LT's but know they are very good powders. Did you preload with it before match day?



Now for the quoted section above, I have the same thoughts for shooters not willing to learn what it takes to keep a gun in tune and stay on set and forget. Our equipment may be equal at their best, but when the set and forget guy "can't make anything work", I have a way to adjust to make it happen. I have witnessed that one for years as well. Do not underestimate the guys that are willing to actually learn the adjust when needed side. The mindless twisters that do not know where they are going or why with an adjustment I actually have empathy for. They recognize there is some sort of issue or problem and at least they are trying something to improve things and their chances of doing better.

Tad

Always game for an intelligent conversation about BR of any type and yes there will always be debate, especially with RFBR. The CF guys generally have a far different type of mindset for whatever reason.
The LT’s can be great, I won LV @NYS pro/am couple years ago but that was first time I shot LT 32 in an IBS match……it does not like wet/ humid. As said, playing with LT 30 but next I plan to experiment with LT 31, they mix well. Also have had great luck with original pulldown 8208 but that is getting tough to find any more.

As I suspect , lots of twisters likely fall into the camp of a less than optimum barrel as well as tune.

As to your question, never pre load. First off, I ‘m not going to prep that many PPC cases and since I bought a Machmaster loading between relays is pretty fast, always go to the line with 20 cases in rotation…l10 sighters, 10 record cases

 

[TRSR8]

I just have to wonder how many times the "set it and forget" crowd have gone to a match and found their rifles' preferred lot just wasn't shooting worth a darn. Then rather than move the tuner a click or two they futzed around with different lots losing points and places. Just something for thought.

I am not looking for a peeing contest either I also just want for someone to explain the physics behind why they believe barrel harmonics behave differently on a rimfire than a centerfire. I am willing to learn and change my opinions but I need something besides "that is what I was told" by someone to convince me

No you’re not willing to learn, you have pre concieved notions and you’re going to the grave with them.
And FWIW, I shoot, and have shot with several gold HOF, shooters and very few of them come to a match with “ several lots” friend, including myself, other than occasionally breaking in a new lot.
FWIW, when the absolute best builders in the history of RFBR tell you the same thing, it pays to listen there new guy.

 

[kevin nevius]

I was really just hoping you or anyone could help me learn how there is one spot on a tuner that shoots everything, all the time, to its full potential. I'm still looking for that, not any pee'ing matches...just solid info that makes any sense, physically. Thanks for your reply.

There has been a lot of great information shared in this thread - not trying to argue, just sharing some personal experience.

Personally, I don't believe any of the "stopped muzzle" theory that has persisted for years. Here at the engineering firm where I work, we have some fairly sophisticated FEA software and although it is difficult to model all that is happening when a round is fired, there is no scenario where the muzzle stops.

I believe what we are doing is manipulating mass (with a tuner) to "time" an exit point within the movement of the muzzle to a repeatable position. In most scenarios, factoring in gravity, the muzzle movement is elliptical - and what I think we are doing is timing the exit point to the furthest point in the exit oscillation, where the muzzle slows, stops (for a millisecond) and reverses direction. That's why I think the crown position is so important - it needs to be located close to that preferential exit point to have any hope of fine tuning it the rest of the way.

I also don't believe in a "set it and forget it" tuner position. I think that's probably true if the muzzle velocity of every lot you will ever shoot in that barrel is constant - but velocity changes the exit position (the bullet arrives at a different point in the oscillation). And I have seen too many examples as I start a new season with a new unknown lot of ammunition (and re-run my typical tuner position testing) that the setting changes. Sometimes small amounts, sometimes not.

Something else to think about, I have also (before the pandemic) been fortunate enough to have larger more comfortable case quantities of a known lot. And as I progressed through the supply, the performance changes - sometimes mandating validation or retesting. As we shoot thousands of rounds through these barrels, they wear, change very slightly dimensionally and with regard to surface roughness (and the ability to carry lubricant). Barrels last a long time if cleaned properly, but that doesn't mean they don't change throughout the course of their useful life.

I know this is not conventional RFBR wisdom, but RFBR is not the only RF sport where only the absolute best regarding mechanical performance and accuracy are capable of winning on the National (or International) stage.

And out of the complete humility this sport has taught me..........I am very well aware that I could be COMPLETELY wrong. Lord knows, it wouldn't be the first time!

Still learning every day (I guess that's what keeps us all coming back!).

Thanks for all of the contributions to this thread,

kev

 

[Tim Slater]

I truly believe that is the single most important decision I made to help improve my rifle's performance by using the Nevius chamber.

Lee

Lee (and Kevin too),

If everyone will permit (or even notice) a slight tangent, in your experience is Kevin's chamber more tolerant of length than match chambers that engrave more?

I don't know if any UK gunsmiths even have a Nevius reamer, but it's food for thought for when my Schneider eventually goes south (assuming Mrs Tim kiboshes a KK500).

 

[gunsandgunsmithing]

There has been a lot of great information shared in this thread - not trying to argue, just sharing some personal experience.

Personally, I don't believe any of the "stopped muzzle" theory that has persisted for years. Here at the engineering firm where I work, we have some fairly sophisticated FEA software and although it is difficult to model all that is happening when a round is fired, there is no scenario where the muzzle stops.

I believe what we are doing is manipulating mass (with a tuner) to "time" an exit point within the movement of the muzzle to a repeatable position. In most scenarios, factoring in gravity, the muzzle movement is elliptical - and what I think we are doing is timing the exit point to the furthest point in the exit oscillation, where the muzzle slows, stops (for a millisecond) and reverses direction. That's why I think the crown position is so important - it needs to be located close to that preferential exit point to have any hope of fine tuning it the rest of the way.

I also don't believe in a "set it and forget it" tuner position. I think that's probably true if the muzzle velocity of every lot you will ever shoot in that barrel is constant - but velocity changes the exit position (the bullet arrives at a different point in the oscillation). And I have seen too many examples as I start a new season with a new unknown lot of ammunition (and re-run my typical tuner position testing) that the setting changes. Sometimes small amounts, sometimes not.

Something else to think about, I have also (before the pandemic) been fortunate enough to have larger more comfortable case quantities of a known lot. And as I progressed through the supply, the performance changes - sometimes mandating validation or retesting. As we shoot thousands of rounds through these barrels, they wear, change very slightly dimensionally and with regard to surface roughness (and the ability to carry lubricant). Barrels last a long time if cleaned properly, but that doesn't mean they don't change throughout the course of their useful life.

I know this is not conventional RFBR wisdom, but RFBR is not the only RF sport where only the absolute best regarding mechanical performance and accuracy are capable of winning on the National (or International) stage.

And out of the complete humility this sport has taught me..........I am very well aware that I could be COMPLETELY wrong. Lord knows, it wouldn't be the first time!

Still learning every day (I guess that's what keeps us all coming back!).

Thanks for all of the contributions to this thread,

kev

Thank you Kevin. Conventional or not, you and I are on exactly the same page.

 

[TRSR8]

Kev, very interesting about the changing ammo.
Actually at our last registered match I dragged out some of that great 2012 ELEY match to shoot. That particular lot shot as it always has but i was concerned about the age.
Have your lot changes been consistent with most long term lots.

 

[grauhanen]

Something else to think about, I have also (before the pandemic) been fortunate enough to have larger more comfortable case quantities of a known lot. And as I progressed through the supply, the performance changes - sometimes mandating validation or retesting. As we shoot thousands of rounds through these barrels, they wear, change very slightly dimensionally and with regard to surface roughness (and the ability to carry lubricant). Barrels last a long time if cleaned properly, but that doesn't mean they don't change throughout the course of their useful life.

Barrels can't remain unchanging. With regard to the ammo, is it possible that over several cases a lot has variation within it, that it's not always equally identical throughout? If so, together with barrel change over time, there would be change in what's seen on target.

 

[gunsandgunsmithing]

Smokeless powder turning from a solid to a gas is a chemical reaction and all chemical reactions, are to varying degrees, temperature dependent. Agreed so far? Hope so because that's just physics and is not even debatable, logically.

If so, how can we expect the same exit times with different pressure curves and/or velocities from temp changes, much less totally different lots of ammo? I can tell you that it happens but it's a result of testing and or luckily stumbling across ammo that exits at a sweet spot..not necessarily, nor even likely the same one.. and sweet spots repeat at specific intervals. Remember where I mentioned different cf loads working equally well as one another? It happens. Same with ammo lots. Without a tuner, this is tuning ammo to the rifle, both rf and cf. With a tuner, it's the same but we're tuning by changing lots of ammo to our rifle at a specific tuner setting. I've seen many times where good lots would be passed by if I wasn't willing and able to properly adjust the tuner/rifle to the new lot of ammo. Same with rf and cf, again.

Something for open minded people to test for themselves but if you do so without knowing how far to move the tuner, you'll be like so many and get lost right from the start. The number one mistake I see from folks is moving the tuner WAYYY too much at a time.

 

[JimSC]

The number one mistake I see from folks is moving the tuner WAYYY too much at a time.

that is the first thing you taught me back when I bought my first real tuner from you and it has served me well. I have seen 3 clicks can take you from hero to zero whether it be a 6BR or a 22LR

the only other real observation that I have made is that tunes run in cycles and repeat themselves

sometime this winter I want to test the vertical and chrono on some rimfire ammo that is at 30F versus some that has been warmed with a handwarmer and/or left in the truck with the heater running

 

[dannyjbiggs]

Smokeless powder turning from a solid to a gas is a chemical reaction and all chemical reactions, are to varying degrees, temperature dependent. Agreed so far? Hope so because that's just physics and is not even debatable, logically.

If so, how can we expect the same exit times with different pressure curves and/or velocities from temp changes, much less totally different lots of ammo? I can tell you that it happens but it's a result of testing and or luckily stumbling across ammo that exits at a sweet spot..not necessarily, nor even likely the same one.. and sweet spots repeat at specific intervals. Remember where I mentioned different cf loads working equally well as one another? It happens. Same with ammo lots. Without a tuner, this is tuning ammo to the rifle, both rf and cf. With a tuner, it's the same but we're tuning by changing lots of ammo to our rifle at a specific tuner setting. I've seen many times where good lots would be passed by if I wasn't willing and able to properly adjust the tuner/rifle to the new lot of ammo. Same with rf and cf, again.

Something for open minded people to test for themselves but if you do so without knowing how far to move the tuner, you'll be like so many and get lost right from the start. The number one mistake I see from folks is moving the tuner WAYYY too much at a time.

Soooooo then...should the OP and I put you in the column of folks that would tunnel test a variety of RF ammo lots with "tuner-off", at least initially?

 

[gunsandgunsmithing]

Soooooo then...should the OP and I put you in the column of folks that would tunnel test a variety of RF ammo lots with "tuner-off"?

Nope. I firmly believe good lots get passed over by shooters and test centers. They are providing a service based on demand for it from shooters. Without adjusting for individual lots, I see very little value in testing at the centers. Now, if they allow me say 2 or 3 tuner adjustments per lot, I feel pretty good that I can pick a good one anywhere and that it'd make their ammo look good too.

I mean simply, I've seen how big the wrong tuner setting can make one shoot as well as how small when in tune. I don't understand the logic that a tuner can only help group size unless it simply brings it into or at least closer to in tune. You have the very same chance to be completely out of tune as you have to be in perfect tune, just leaving it set and changing ammo randomly. More likely, you're somewhere in between, though. IME, completely out of tune with a tuner is bigger than without because there is more amplitude with a weight hanging on the end. Physics teaches us just the opposite but vibration analysis proved to me that in the very short period while the bullet is still in the bore, amplitude is actually increased rather than decreased. Yes, it dissipates faster than without the weight at the end but the bullet is gone either way. That came from testing, both in a lab and live fire. Otherwise, I would have just assumed it to be the other way around.