What should a tuner be expected to do?

[wallz]

A tuner does indeed alter the barrel. It does nothing to the ammo itself. When the tuner is adjusted to the optimal setting, it should work all with good lots of ammo because of what it does to the barrel, completely independently of the ammo itself.

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VERY great info here. I do think there is some correlation to the ammunition. I think the pressure created in the barrel as the bullet goes down and powder burns help to create the barrel whip. This would show a slight tuner setting difference with ammo type, which is usually different speed and most definitely seats differently in the chamber. I think the chamber cut and barrel cut will also play with the barrel whip, because that is influenced by the bullet again as it exits and the pressure created in the barrel.

I have no way of proving this, but this is what I have seen when going from sk long range match, to center X, to midas +. They each have a "best" tuner setting. While still shooting relatively okay on each different setting, they still have a best at a different point.

I have seen this on my 6.5 CM as well. Same bullet, same everything but powder and the barrel whip is different. Granted I have more control here, as I can tune the load, before I even touch the tuner setting, but to me is shows that the pressure created with the different powders also plays a part. I am currently finishing a batch of 130 gr vld, and am prepping my next load for 139 gr scenars. I have the 130 vld set at 'bullseye" at 100m. The 139's with RL16 impacted roughly 2" lower on target at 100M than setting at zero, and the same 139's with N555 are impacting 2" higher than zero and bit left. Showing me I have a different whip on that barrel.

 

[Williwaw]

Morning all. My comments will be organised as per the previous posters sections.

Section 1

I've plotted graphs similar to this before and have not seen a steady down to the right trend. If such a trend was predictable and reliable I think the word would have got out and the widespread advice would be work back from 500(eg.on a Harrell). In fact if anything I would say just the opposite is true.

Section 2

The way I think of it every lot of ammo has a profile, some are prettier than others. A good tune can't fix everything but it does produce better scores for me in the long run. That is, I find a tune that is effective in reducing MV variation induced dispersion for the greater part of the profile.

Section 4(second post)

Your concluding sentence is exactly what I have had to do with SKSP but not necessarily with RM or LRM. I ignore the wonky rounds as noise and determine my tune on the basis of the 80 to 90 percent that are behaving. That seems like the best way to go and in the end I get better scores.

 

[adamg]

Your concluding sentence is exactly what I have had to do with SKSP but not necessarily with RM or LRM. I ignore the wonky rounds as noise and determine my tune on the basis of the 80 to 90 percent that are behaving. That seems like the best way to go and in the end I get better scores.

I'm beginning to agree with this approach. The fliers in rimfire are going to be wild and ugly, no matter what the tuner is set to. The only hope we have of achieving something worthwhile with the tuner is to only consider the affect its setting has on the consistent shots.

 

[Mystic Precision]

I am glad to see that the consensus has moved to confirm a tuner does SOMETHING to a barrel.

I am also happy to see that more are understanding that rimfire ammo is by precision ammo (centerfire) standards, problematic ( I was going to say CRAP but some might take offense to that).

I am tuning/testing for a combo where the 'out' will hopefully stay inside the intended target but accept, often, it will not.

I really don't think we will see truly consistent match ammo (better then 95%... right now, I would be thrilled with better then 90%) given how poor past batches have been and now the massive surge in demand globally. In fact, I expect to see performance get worst per dollar spent.

So have changed my approach to the cost and testing. Close enough, seems to be about all I am willing to invest in going forward

YMMV

Jerry

 

[Williwaw]

But it says on the front page of this sub forum ....RIMFIRE fun stuff that won't break your piggy bank

 

[grauhanen]

I am glad to see that the consensus has moved to confirm a tuner does SOMETHING to a barrel.

Jerry, except for a few skeptical posts about the efficacy of tuners early in the thread, the consensus here has always been that a tuner does something to the barrel.

VERY great info here. I do think there is some correlation to the ammunition. I think the pressure created in the barrel as the bullet goes down and powder burns help to create the barrel whip. This would show a slight tuner setting difference with ammo type, which is usually different speed and most definitely seats differently in the chamber. I think the chamber cut and barrel cut will also play with the barrel whip, because that is influenced by the bullet again as it exits and the pressure created in the barrel.

We can agree that without rounds going through the bore there wouldn't be any harmonics, vibrations, or "barrel whip". The question is how much, if any, difference, occurs in the "barrel whip" itself by ammos with different velocities.

Consider that every box of ammo -- every lot of ammo -- will have a range of muzzle velocities or extreme spread. Some will be quite large. Entry level match ammos, for example, can be expected to usually have a larger ES than better grades (not always, but usually). Can a tuner "deal" with ammos that have a wide range of MVs? That is to say, will a tuner work on ammo that has an ES of 50 fps or 75 fps? Will the "barrel whip" be the same or similar for all rounds within a large ES? Or would the tuner work for only some of those rounds but not all of them, perhaps only those that aren't "too fast" or "too slow"?

I'm not sure I know the answer.

 

[wallz]

I think with a spread of 50 fps to 70 fps they will disperse differently and the tuner will not be capable of "bringing" those wild ones in. I think with the small fps of 22 ammo to start with, the spread near and above 50 fps will and does make the difference.

Again I keep going back to my center fire results that I see as well. I usually do a ladder test for a new load, and don't use, don't own, a chrony. For something like the 6.5 creed there is no point in testing a large area between min and max loads, as it has been proven to like the range between 41 grains and 42.5 grains. I start in that range and shoot a ladder test at 200 m. I will see a change in impact point even with a 0.2 grain difference. I mean sometimes 3" difference, and while I can't always say it is the load, or barrel whip, as some will be human error, it is always interesting to see the results. I then am able to find the sweet spot of the barrel to that bullet/ powder combo, and go fine tune it from there.

We can't do this with 22lr, so finding a sweet spot of speed, bullet make combo is more difficult and changes with each barrel type, cut, and composition. I run a take down 10/22 with a volquartsen barrel as my hunting rifle, and found the best bullet (bang for buck) in it to be Eley action. Don't know y, but it just consistently prints decent groups with it. I would much rather shoot a hollow point as a hunting round, but have not been able to find one that prints with any decent groupings with it, and trust me I have tried most of them out there in HP. Granted I have not tried midas + or center X thru it, but can't justify the price of those as a hunting round that gets used lots for plinking.

That brings in the whole concept of human error in all this. I have shot lots in the last 10 or so years since diving deep into shooting/hunting, and have shot more center fire in the last two years than the previous 8 before combined. Can't even count the amount of 22 that I have pulled the trigger on since then, and I still have a ton of human error in my shooting. Just the combo of all those things put together is enough to drive a person insane as we try and rabbit hole figuring it all out. Just last night I ran a new load in the 6.5 cm, and wanted to verify my load before I load up hundreds of rounds, and off to the range with 10 rounds. Six were pretty much in the same hole, with 4 flyers around it out 1/2" from the group. It was kinda 2 grouped, 1 pulled, kinda scenario. I know those were pulled by me as soon as I pulled the trigger. Too much pressure to one hole 10 shots and I had to screw it up.

 

[grauhanen]

Section 4(second post)

Your concluding sentence is exactly what I have had to do with SKSP but not necessarily with RM or LRM. I ignore the wonky rounds as noise and determine my tune on the basis of the 80 to 90 percent that are behaving. That seems like the best way to go and in the end I get better scores.

I'm beginning to agree with this approach. The fliers in rimfire are going to be wild and ugly, no matter what the tuner is set to. The only hope we have of achieving something worthwhile with the tuner is to only consider the affect its setting has on the consistent shots.

Here is one of the great conundrums of serious rimfire shooting. Flyers or wonky rounds are not responsive to tuners. There's little if anything that a tuner can do to make such rounds fly true. In other words, with or without a tuner they will screw up groups or scores.

The alternative is to use the best lots of ammo, the ones in which flyers or wonky rounds are rare. Serious and experienced BR shooters say that fliers are very rare in .22LR match ammo. The amateur ballistician and BR shooter to whom I referred in post #65 said the following less than a year ago about flyers:
"There’s not a forum in existence where it’s not a popular topic, but the fact is they are incredibly rare with true match ammo the likes of Lapua Midas, X-Act, Eley Match, Tenex, and RWS-50." (See post #28 here h ttps://www.rimfireaccuracy.com/Forum/index.php?threads/a-visual-of-a-match-target-being-shot-my-way.30055/page-2)

Unfortunately, and with all due deference to more experienced and knowledgable shooters, those kinds of lots don't seem to be easy to find. Considering how often I've seen what I can only describe as flyers or wonky rounds in the Midas I've had, I can only guess that here in Canada we don't often get the best lots of .22LR match ammo. Almost every box of Midas I've used in recent years, including from four lots this season, has had a surprise or two (sometimes more). When there's a box without a surprise from an otherwise good lot, the results can be quite satisfying. But I wouldn't count on any box from any lot of Midas I've had.

When shooters do have good ammo, tuners can improve it. In this thread in post #28 Toolman, an experienced shooter, shows what a tuner can do with good ammo. In his own words the tuner produces "a slight reduction in vertical". It's not miraculous. And its not so great as to be dramatic. But it can improve the score. The question of how much tuners can change the performance of less than consistent ammo remains unclear.

 

[Williwaw]

We can agree that without rounds going through the bore there wouldn't be any harmonics, vibrations, or "barrel whip". The question is how much, if any, difference, occurs in the "barrel whip" itself by ammos with different velocities.

.

I have to disagree here ... the question is not differences in barrel whip due to differences in velocity. The pattern of barrel oscillation is relatively repeatable regardless of velocities. It is that repeatability that in part determines the efficacy of a tuner position. Differences in velocity result in different exit times and as the barrel is moving different exit times canhave different launch angles. I say can to respect the devotees of the stopped muzzle.

 

[emerson]

I'm beginning to agree with this approach. The fliers in rimfire are going to be wild and ugly, no matter what the tuner is set to. The only hope we have of achieving something worthwhile with the tuner is to only consider the affect its setting has on the consistent shots.

I think that makes sense.

 

[Williwaw]

A tuner does indeed alter the barrel. It does nothing to the ammo itself. When the tuner is adjusted to the optimal setting, it should work all with good lots of ammo because of what it does to the barrel, completely independently of the ammo itself.

I'll offer an alternative to this position. A tuner alters neither the barrel or the ammo but the relationship between the barrel and the ammo. Thus a good setting with one lot may require no adjustment with other lots with similar velocity distributions/profiles. I am not theororizing here, this has happened to me with some Cx. More often adjustments have to be made because of differences in the velocities/exit times in order to bring the rifle/ammo system back into tune.

I did some more tuner testing tonight in excellent conditions. I will try to overcome the technical difficulties I've had posting pics(I'm clueless)in the morning. It is a textbook example of what I look for in a tune along with a couple fliers that I ignore as per previous posts.

 

[grauhanen]

I have to disagree here ... the question is not differences in barrel whip due to differences in velocity. The pattern of barrel oscillation is relatively repeatable regardless of velocities. It is that repeatability that in part determines the efficacy of a tuner position. Differences in velocity result in different exit times and as the barrel is moving different exit times canhave different launch angles. I say can to respect the devotees of the stopped muzzle.

It's unclear with what you disagree. To reiterate, I suggested that "The question is how much, if any, difference, occurs in the "barrel whip" itself by ammos with different velocities."

I'll offer an alternative to this position. A tuner alters neither the barrel or the ammo but the relationship between the barrel and the ammo. Thus a good setting with one lot may require no adjustment with other lots with similar velocity distributions/profiles. I am not theororizing here, this has happened to me with some Cx. More often adjustments have to be made because of differences in the velocities/exit times in order to bring the rifle/ammo system back into tune.

The view that a tuner "alters...the relationship between the barrel and the ammo" is true in that it's saying that without the tuner on the barrel nothing changes.

___________________________

Below are some serious questions for any reader interested in rimfire tuners. I suspect that the first two questions should have little disagreement.

If it can be taken that tuners work according to laws of physics that are understandable (even if not currently agreed upon), can there be more than one valid explanation for how they work, whatever it may be? In other words, can one phenomenon be explained by two different ways of describing how physical things work?

Can positive compensation occur with a tuner at the same time as a "stopped muzzle"?

Will an effectively adjusted tuner reduce group sizes of good and consistent ammo at 50 yards by 10% or 15% or 20% or 25% (or more)? By way of example, at 50 a ten-shot group of .500" that's reduced by 25% would be .375".

Will an effectively adjusted tuner function usefully with all .22LR ammo?

Can the effectiveness of a tuner be accurately assessed with ammo that has flyers or wonky rounds? If so, without knowing the MV of any round, how would a shooter determine which rounds qualify as flyers or wonky? Are they simply those that do not have the desired POI?

 

[fiftycalforsquirrels]

I didnt read much of the thread...bits here and there. General response in regards to the first post.

If I was using a tuner, I would expect it to be set properly when it shows the results on paper to be a tighter group than without the tuner.

For adjusting one, I would adjust it all the way one way to an extreme to find the group size at that point, and grossly adjust it in untill it shows groups tightening. I would then adjust it all the way to the other end of the extreme and adjust in until it shows group tightening. That should be the inside limit to where the tuner is going to have an effect. I would then make fine adjustments inside that range until I reasonably thought it was set to give the best vertical reduction deviation.

Instead of shooting groups, I would try shooting 1 bullet at 1 point of aim. May better be able to recognize what the single bullet is doing in relation to a set point of aim and intended point of impact.

 

[wallz]

I didnt read much of the thread...bits here and there. General response in regards to the first post.



Instead of shooting groups, I would try shooting 1 bullet at 1 point of aim. May better be able to recognize what the single bullet is doing in relation to a set point of aim and intended point of impact.

You will need a group no matter how you look at it. Take different ammo, and even without a tuner the point of impact will be different to the point of aim for all different ammo in your barrel. You will not be able to draw anything from knowing I was aiming at point A and hit at point B without shooting a group. Different velocity will create different whip, which will create different exit times in that whip, and send the ammo to the different areas of that whip. (if you take a few of the last posts and kinda summarize them together)

When you are tuning the tuner you don't care were the impact point is, but that your impacts are close together. You can always set the scope to point of aim and point of impact, and most even like to have point of impact higher than point of aim, so it does not interfere with point of aim.


Its like having to great of settings between shots you may also miss a great area that aligns the velocity/ pressure/ whip/ for the ammo you are trying to "tune".

 

[fiftycalforsquirrels]

5 shots at 5 different aim points, measure deviation from point of aim where point of aim is point of impact, and you have your "group". The difference is you would be taking the precise measurement of 1 shot vs the average of 5....should be 500% more accurate than shooting 5 at the same point of aim and taking the average of 5.

You would need something to measure off of if shooting 1 shot groups. That something would be a horizontal line running through the point of aim.

Just a theory. I said I would try it... doesnt mean its worth the pixels it took to write it.

 

[Williwaw]

Hey fiftycal, what is the going rate for a pixel.

I do a version of what you describe by scanning and digitizing the five shot groups and generating statistics using OnTarget. There is some ambiguity in locating the hits precisely but there are other advantages to having groups. I'm trying to find the time to post all of the targets and OnTarget results for the tuning that I am currently doing.

EDITI've just been approved for the Equipment Exchange, may not be heard from for days ...

 

[Canuck65]

A tuner might squeeze that last .25MOA out of your groups, but that's it. Maybe it'll save a less-then-great barrel from the scrap bin. Some of the guys in our club that haven't yet sprung for a proper benchrest target rifle still use them with some success. One guy got his CZ to compete head-to-head with the Annies with just a bit of stock work and a rubber slip-on tuner. Since then though, He's bought an Anschutz and turfed the tuner.

I think that with a quality rifle , quality barrel, and quality ammo, a good rest and LOTS of practice, the tuner is redundant. If you're having trouble closing up your groups, try moving the rifle forward or backward on your rest - or try tightening the ears on the font bag to prevent some or all rearward movement - or more or less cheek pressure - or more or less shoulder pressure - or taking your body and hands completely off the rifle and just pinch the trigger and the rear of the trigger guard with your finger and thumb - or, or or or .....

It's a frustrating and challenging sport. Practice and a quality rifle will make you better, not accessories and gadgets. Just my 2 cents - others will disagree.

 

[Williwaw]

First image is 5 shot groups at consecutive tuner positions. I have already shot the lowest 100 positions by two. Hi-graded and passed on anything in the first 50 and now this is the hi-grade for the next 50. 46-59 contain a good tune, 37-42 a stopped low position, likely 40.

51 and 58 are 6 round groups, both contain a high left impact. It is worth noting that in shooting this lot without a tuner it has thrown 4 and 0 outright fliers in 40 round sessions. Settings 46 to 59 represent 70 rounds and I'm claiming two mulligans in my testing today.

 

[Williwaw]

So that was on its side, I'll keep trying. This next is out of OnTarget. It is settings 49,50,51 overlain using the poa as reference. A good PC tune should not only group well per setting but a few settings on each side often have a stable group size and stable or slowly rising POI.

 

[Williwaw]

This one is 49 to 54 with same poa reference. Note that I've edited two rounds which I consider wonky. So this is 13 more rounds over six consecutive settings. I won't talk about the statistics, you can see them for yourself.