Testing smallbore ammo lots: tuner tube on or off?

[VLNBYR]

Shane at the Lapua Test Center works with a bunch of rifles every day five days a week. Some of these rifles are big time winners, some of them are probably dogs, most of them are probably average. They all go through the same lots so there is opportunity there to observe whether some lots stand out across the board. I know there was one lot that had failed to shoot decent in any rifle for weeks of testing. Just for kicks we ran it through my rifle and it didn't do too bad, Shane was impressed, I wasn't surprised.

 

[wkdickinson]

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.

WOW! I just got back from a session at Lapua Marengo. I tested 2 rifles, both with turners set to where I have been shooting them. I found a lot that shot good in each rifle, but they were different and only being able to purchases one case, I bought the one for my ARA rifle. My problem with this whole discussion is that there is CF tuner experiences interspersed with RF and they are totally different (maybe not in theory, but certainly in practice). Mike, I have 2 of your CF tuners and I get it, I am a believer, they work!!! But RF is a totally different world.

I thought I had somewhat of and understanding, but I am not sure that is truly the case, the more I read.

 

[gunsandgunsmithing]

WOW! I just got back from a session at Lapua Marengo. I tested 2 rifles, both with turners set to where I have been shooting them. I found a lot that shot good in each rifle, but they were different and only being able to purchases one case, I bought the one for my ARA rifle. My problem with this whole discussion is that there is CF tuner experiences interspersed with RF and they are totally different (maybe not in theory, but certainly in practice). Mike, I have 2 of your CF tuners and I get it, I am a believer, they work!!! But RF is a totally different world.

I thought I had somewhat of and understanding, but I am not sure that is truly the case, the more I read.

RF is certainly a a different animal but as far as an adjustable weight on the end of a steel tube...not a lot. There are differences in how they tune but the principles don't change, ime. I'm not here telling anyone to change what works for them. I just have a different approach that works too. I go over it by phone on virtually every order so it shouldn't be a surprise, though. You can call me anytime if I can help in some way.

 

[Intell]

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.

I’m a set and forget also, mine are actually taped so they doesn’t accidentally get turned on me while I’m away from my gun during a match.

Right or wrong, on a calm day I tune to where slow and fast ammo 1020 to 1080 range both shoot tiny groups, not the same point of impact, just small. I can usually find 2-3 places on my tuner where that happens. Then I shoot some score targets to verify.
Now wait until a windy day where the flag tails are ripping and switching then re test those 2-3 tuner settings on score targets and one setting will cut through the wind better than the others, that’s when I call it tuned. This is when tape is applied.
If it’s fed good ammo of any speed, it shoots well. I don’t try to force the gun to shoot crap ammo better, I call it crap and move on to another lot.
What I described may not be the best way, but it works for me.
Happy shooting

 

[dannyjbiggs]

I have been using an Uptagrafft tuner tube on my Anschutz 2013 for the past outdoor smallbore prone season over the summer, and I am very happy with how it dialed in my groups. Now I am ready to test some new lots of ammo. My questions is, do I lot test with the tuner tube on or off? I know the tuner can round out groups and tighten them up, but I also know that if it is not properly tuned it can make groups worse.

So my thinking it do my lot testing with the tuner off the gun, then put the tuner tube back on to get the most out of the best lot? Please advise if I am on the right track here.

For reference, I normally do my testing at 100 yards.

Not knowing a lot about your rifle or ammo, I think your idea has merit. That's exactly what I did starting out. Initially I burned thru 1,000 rounds or more on a new rifle, then got a mediocre lot of Center-X from the Mesa Lapua Test Facility, which was tested tuner-off, and then burned thru another 600-800 C-X rounds fretting with a Harrel tuner, which proceeded to turn a wicked witch into a Cinderella. Thereafter, I tested X-Act at the Marengo Lapua Test Facility, tuner-off. And promptly had my best showing lot re-tested, tuner-on (with my otherwise set-and-forget tune at the moment), for a noticeable improvement. In about three weeks, I plan to tunnel test Midas+ at the Mesa test facility. And you guessed it: Initially tuner-off, followed by tuner-on of any promising lot(s) with my at the moment set-and-forget tune.

I'm sure you will be testing your prone rifle using sandbags/rests off-the-bench, and I would recommend first testing at 50 yards.

 

[Hi-NV Shooter]

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.

Thanks, Tad, for your detailed reply I do appreciate your sharing. I have had a few forum exchanges with I believe is your dad, Todd? you are absolutely correct in trying to shoot different rifles off one rest is challenging. I have noticed one likes to shoot at a slight upward angle another level or slightly down and my best can shoot at any position and the stock on this rifle is supposedly not ideal for BR as it has an angled butt and is not Straightline.
I do agree ignition is very important as it plays into getting good consistent shooting ammo poor ignition will even make the best lot shoot very flaky at best and terrible at worst. because of the importance of ignition, it is reason I like to tune in temperatures below 60 degrees with 48-50 being ideal for me.
my reasoning is to have the lowest velocity to time the bullet's exit.
As I mentioned for me and my rifles whenever a rifle is not shooting how it should be it is always something to do with recoil management. and since it is part of the tuning equation maybe what I am seeing is an out of tune rifle if that is all I am experiencing for being out of tune then I am very fortunate as the fix is very simple. I guess it can be equated to a 1-2 click tuner adjustment as making that small of an adjustment is simples as well. lot of information to think about.

Thanks,
Lee

 

[Hi-NV Shooter]

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).

Tim, I believe with less engraving the bullet has from the chamber the more forgiving it will shoot. meaning finding lots is not as critical. this is the only conclusion I can come up with as to why my rifles can shoot most lots without testing.
Kevin may remember awhile back I reached out to him on how bore diameter could change engraving length even if using the same chamber specs. I was getting engraving of about 0.080 or just about the width of the first driving band where I should be getting only 0.030 at most. it shot very good, but it was very finicky on what it shot good with. I had the chamber deepened to give the 0.030 after that the same lots that were finicky shot really good. in fact, the rifle gave me my first ARA win.
This has been my experience using the minimum engraving the Nevius chamber provides.

Lee

 

[Tim Slater]

Lee,

Thank you. Have you found the chamber accommodating of shorter cartridges? Or is too little engagement as bad as too much?

 

[Hi-NV Shooter]

Lee,

Thank you. Have you found the chamber accommodating of shorter cartridges? Or is too little engagement as bad as too much?

You're welcome, Tim. As you know I sort by AOL from the rim face to Ogive. I found that I have a length widow of about .015 the ideal length for my best shooting rifle is 0.720 so it will shoot very good with measure rounds of 0.705-0.720 now anything below or above it will not shoot as good or tight. it is not that it will shotgun pattern but maybe put one a bullet diameter outside the group or drop out or go up out of the ten ring. shorter lengths generally give the shot that go up and out and longer lengths are the droppers.(see attached target bulls 8,13, & 24 are what I mean. bull 2 was just a whisker inside)

as a side note: I believe why Lapua dominates RFBR is because the ammo is very consistent in length. over the years I have been seeing this consistency get better and better. I just got 5 bricks of CX and I am getting sorted groups of 0.690-.695 and 0.700-.705 that is only 0.010 spread between the longest length for each group out of 500 rounds. also, there is less than 30 rounds that are outside of these groups. but even these are consistent as well. 0.685 and 0.710-0.715 in the past I may have gotten as much as 4 or 5 different length groups. with spreads as much as 0.030

Going back to what I said about the Nevius chamber being forgiving here is a target I shot this past Sunday with a 0.690-0.695 sorted CX this is the first time I shot this lot in this particular rifle it prefers 0.720 as ideal length. and for those who might be wondering the tuner has been set at the same setting for the last 8 years.
I bought this lot about 5-6 months ago blind no testing. 323 mps is the box speed. you can bet I will not have a barrel chambered any other way!

Lee

 

[Hi-NV Shooter]

my327vette sorry about blowing up your thread. sometimes I forget why I posted to the thread and forget what it was originally about.
but I stand by my first post use your best lot scores as the base line to decide with or without the tuner.

Lee

 

[JimSC]

From your measurements it looks like you have a comparator insert that is measuring farther down on the ogive than mine does

using a Hornady comparator body with the Hornady .22 caliber insert I find Lapua/SK/RWS to be around .762 plus or minus .002 while Eley runs about .010 shorter at .750 plus or minus. For CZ's the Lapua/SK/RWS ammo shoots much better than Eley although I did have some luck with a particular lot of Match

At the risk of bringing the center fire into the conversation again this reminds me of setting the seating depth when developing loads.

Back to the OP I think the idea of testing tuner on adjusted out 4 turns seems the most logical suggestion I have read

 

[Hi-NV Shooter]

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

I agree Kevin it is about barrel movement and the pattern it travels in and timing the bullet's exit correctly. IME find the exact spot for that rifle /barrel, and I don't need to adjust the tuner again.

I also believe in using just the right amount of weight on the barrel. all of my tuner settings are below 100
using less than 5-oz. tuners. it goes back to shooting bare barrel to get an idea of how it will shoot. if I get a sub .200 group I don't want to put 8-oz of weight on the barrel as I know it will be harder to get it to shoot consistently sub .200 with different lot speeds. I want just the amount of weight to time the exit for the ammo's velocity variables.

Lee

 

[Hi-NV Shooter]

From your measurements it looks like you have a comparator insert that is measuring farther down on the ogive than mine does

using a Hornady comparator body with the Hornady .22 caliber insert I find Lapua/SK/RWS to be around .762 plus or minus .002 while Eley runs about .010 shorter at .750 plus or minus. For CZ's the Lapua/SK/RWS ammo shoots much better than Eley although I did have some luck with a particular lot of Match

At the risk of bringing the center fire into the conversation again this reminds me of setting the seating depth when developing loads.

Back to the OP I think the idea of testing tuner on adjusted out 4 turns seems the most logical suggestion I have read

Exactly I am using what CF shooters have known for some time and applying it to RF. I have friends who shoot CFBR and they confirm what I believe I am doing by sorting.
I also know cast bullet CF shooters do the same thing. in fact, they use a special loading tool which can be set for different inserting depth when loading a round into the chamber of the rifle. if anything, this closely mimics RF in comparison.

Lee

 

[efoleyjr]

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.

So, are you saying that when testing at a test center and not adjusting the tuner that tuner off gives you better chance of finding a" good" lot? And if so should the "good" lot have a good chance of tuning well? Thanks
Ed

 

[JimSC]

getting the correct seating depth is a integral part of developing CF long range loads. Oddly enough I did find one lot of Eley black box Match that shot lights out in my 457MTR. Of course by the time I found that out Killoughs had no more of that lot#. I ordered several boxes of Match which were close to it on FPS, made on the same machine etc but never found another lot that would give me close to the same results

edit - looking back at my numbers most ammo , even the cheap stuff only had a difference of .003 which in CF is not enough to really matter as long as the average is within a couple of thousandths of the barrels preferred jump or jam.

One of the great things is that throat erosion is pretty much a moot factor that is one thing less to worry about

 

[kevin nevius]

getting the correct seating depth is a integral part of developing CF long range loads. Oddly enough I did find one lot of Eley black box Match that shot lights out in my 457MTR. Of course by the time I found that out Killoughs had no more of that lot#. I ordered several boxes of Match which were close to it on FPS, made on the same machine etc but never found another lot that would give me close to the same results

edit - looking back at my numbers most ammo , even the cheap stuff only had a difference of .003 which in CF is not enough to really matter as long as the average is within a couple of thousandths of the barrels preferred jump or jam.

One of the great things is that throat erosion is pretty much a moot factor that is one thing less to worry about

Hi Jim:

I'm a long range shooter also, and the chamber testing I've done is all based on how influential a variable seating depth is in centerfire load development. If we are stuck with factory ammunition, it seemed like a variable worth exploring. From the first tests back in 2011 (I think) until now, I have retested the theory time and again and I am amazed how consistent the results seem to be. That's pretty rare in RF (finding any variable that is completely repeatable! LOL).

And just a quick thank you to Lee - thanks for your kindness and willingness to share. You and others like you are the reason I love this sport.

And to the original OP - my apologies for derailing the thread a little, it was not intended but I have greatly appreciated the information and all of the varying points of view. These forums are very powerful things when people aren't afraid to share.

kev

 

[gunsandgunsmithing]

So, are you saying that when testing at a test center and not adjusting the tuner that tuner off gives you better chance of finding a" good" lot? And if so should the "good" lot have a good chance of tuning well? Thanks
Ed

I hope I'm understanding you right but what I'm saying is simply that I've seen many times where a good lot of ammo did not shoot well at all at a given tuner setting but shot great a few clicks away from there. I want to be able to tune the rifle to the ammo when testing. I see very little value to testing without moving tuning the rifle to whatever ammo I'm shooting. Test center or anywhere, for that matter. Again, I've just seen it even more often than not..that I can not tell much about any lot of ammo until I tune the gun to it. I believe there are no telling how many good lots that get passed over because of this. Tuning allows me to extract whatever potential a gun and load combination have from it. In fact, that's exactly what tuners are for imho.

If I didn't think so, I'd probably put a couple of shaft collars and the barrel to simulate the same weight and just test until I found a lot that shot well like that. I think they're adjustable for that reason. Obviously a tounge in cheek over simplification but yes...that is very much how I see it.

 

[TRSR8]

One final thought here, especially since every/any tuning thread anywhere gets bombarded by friend Mike.
Go over to BRC and read the thread “ How I got here” by Pedro S, especially post 27, all about tuning
Pedro sits as current world champion, sponsored by Lapua and has an unmatched record of accomplishment over several years.
Bottom line, adjustment for weather, ammo, etc……..never.
how much do some of you guys need to be spoon fed before some of this sinks in.
Simply one more guy that wins( the point here) saying the same thing.

 

[gunsandgunsmithing]

One final thought here, especially since every/any tuning thread anywhere gets bombarded by friend Mike.
Go over to BRC and read the thread “ How I got here” by Pedro S, especially post 27, all about tuning
Pedro sits as current world champion, sponsored by Lapua and has an unmatched record of accomplishment over several years.
Bottom line, adjustment for weather, ammo, etc……..never.
how much do some of you guys need to be spoon fed before some of this sinks in.
Simply one more guy that wins( the point here) saying the same thing.

Typical dig Tim. I've said very little here except when quoted. It'd be rude not to reply. I'll give you credit for this...you're a lot worse on other forums than this one. I didn't even recognize your screen name but it didn't take long to figure out who you are. Your famous for being...you.

 

[Hi-NV Shooter]

I’m a set and forget also, mine are actually taped so they doesn’t accidentally get turned on me while I’m away from my gun during a match.

Right or wrong, on a calm day I tune to where slow and fast ammo 1020 to 1080 range both shoot tiny groups, not the same point of impact, just small. I can usually find 2-3 places on my tuner where that happens. Then I shoot some score targets to verify.
Now wait until a windy day where the flag tails are ripping and switching then re test those 2-3 tuner settings on score targets and one setting will cut through the wind better than the others, that’s when I call it tuned. This is when tape is applied.
If it’s fed good ammo of any speed, it shoots well. I don’t try to force the gun to shoot crap ammo better, I call it crap and move on to another lot.
What I described may not be the best way, but it works for me.
Happy shooting

I find shooting for score to be the last factor on seeing that the tuner is set correctly. I also believe to really know if it is tuned it has to shoot in the wind. the ability to hold for the condition and have the shot go where you intended it to only confirms your tune. having the ability to score well with different lots further confirms you are done.
I said this before if you can shoot 250-18X+ or put up 2300+ scores with different lots. and you shoot a lot that only gives you, 245-248 11 or 10 X or 1800-2000 why would you think it was the tune.

Lee