Things learned in the test tunnel

[whiddengunworks]

I've been away at a match for a few days "Living My Best Life" as my kids say.

Concerning cleaning we have no real data. My own experience is that it's highly barrel dependent. I have one that shoots quite well then fouls out between 350-400 rounds. Eley has us clean after we test 15 lots x 10 rounds so 150 rounds total. We clean quite thoroughly with Iosso when we do clean. We do not see a deterioration in accuracy over 150 rounds. If we did, then we'd never see the last lots we test shoot well.

About the tuner, I hope to rerun that test that gave me different tunes for 50M and 100M. I have shot that rifle from the sling since that test, and my own sense is that the two different tunes do indeed hold up in the outside world. We will have an opportunity to test this again at some point.

If barrel diameters matter, it's not obvious to us at this point.

 

[ATFIV]

I've been away at a match for a few days "Living My Best Life" as my kids say.

Concerning cleaning we have no real data. My own experience is that it's highly barrel dependent. I have one that shoots quite well then fouls out between 350-400 rounds. Eley has us clean after we test 15 lots x 10 rounds so 150 rounds total. We clean quite thoroughly with Iosso when we do clean. We do not see a deterioration in accuracy over 150 rounds. If we did, then we'd never see the last lots we test shoot well.

About the tuner, I hope to rerun that test that gave me different tunes for 50M and 100M. I have shot that rifle from the sling since that test, and my own sense is that the two different tunes do indeed hold up in the outside world. We will have an opportunity to test this again at some point.

If barrel diameters matter, it's not obvious to us at this point.

Could lower exit pressures explain some of the barrel length / accuracy relationship?

 

[Pareto]

There are those who claim tuners don't work, despite anecdotal evidence to the contrary. I think we could see very easily without a huge sample by shooting three 5x groups at the optimal tune then 3 more 5x with the tuner off. A simple F test based on measuring distance from center mass would be sufficient. You would only need more shots if the size of the average groups were too similar.

For what it's worth, I use tuners and like them, so that's my bias.

I would certainly like to see this, as well as stat evidence on the 50 vs 100m tunes at both 50 and 100.

 

[Straightshooter1]

There are those who claim tuners don't work, despite anecdotal evidence to the contrary. I think we could see very easily without a huge sample by shooting three 5x groups at the optimal tune then 3 more 5x with the tuner off. A simple F test based on measuring distance from center mass would be sufficient. You would only need more shots if the size of the average groups were too similar.

For what it's worth, I use tuners and like them, so that's my bias.

I would certainly like to see this, as well as stat evidence on the 50 vs 100m tunes at both 50 and 100.

Yesterday, I was shooting 5 shot groups with my .308 (with Timney trigger set at 12oz) favorite loads and getting sub .5 MOA groups. I was a little surprised that the load was doing that well in 100°F ambient temperature (in the shade), though there was some consistent vertical in the groups that I don't normally see. A Harrell Radial Ported Tuner-Brake is mounted on this gun and I thought I'd make an adjustment to see if I can reduce that vertical. Before going on to the next 5 round group I moved the setting from 4 to 5. As I began to take the first shot I actually pulled the trigger before I was actually ready and the POI ended up about 1 MOA low and a little to the right of where my POA is and where the center of the groups were running. I thought, crap. . . I really messed up that shot! Next shot I was careful to do my part and the POI was left of that 1st shot in line with POA, but with with same vertical location. The only thing that I could think of that might cause that was the change I made to the tuner. I couldn't believe, and still find it hard to believe, that change in the tuner made that much difference at only 100 yds. After that second shot, I moved the tuner to the 3.5 position (a little past where I started). The following 3 shot were right on the same POA with nice triangular 3 shot group at ~.3". The following 5 shot groups did just what was expected.

Well, I guess the next time I'm out at the range I'll have to test that setting at 5 to see if it'll actually move that far and in that way again.

 

[dusterdave173]

Our club only allows tuners on the unlimited rifle class
Most of the participation is in factory class as that is where new shooters start
So..ammo selection is the key

 

[Ranger188]

@whiddengunworks
John, when you shoot and find a good lot of ammo for a particular rifle,
do you do any other sorting of that lot? ( rim thickness, weight, OAL )
Or are the groups shot randomly with that lot?

 

[Knotwild]

What exactly is the problem? Tuners were part of the subject. Lots of people read this, some commented on different but related aspects of the thread, and some scrolled on by. One poster condemned people for discussing the thread subject matter. Thank you John Whidden for your testing and the services you offer to the sport..!
I just don't understand people not just scrolling on by, especially vs interjecting things like your post does. Sorry, but I just needed to say that. TIFWIW. Good night.

Sorry but I envisioned a thread where Mr. Whidden reported what he observed on his new test range. So, I envisioned a concise post of observations, not a thread about everyone else's observations. Like every other person's post on this forum, it's just my opinion, and everybody here has them. Like you, some I appreciate, and some I don't. But I enjoy it all.

 

[TRSR8]

Sorry but I envisioned a thread where Mr. Whidden reported what he observed on his new test range. So, I envisioned a concise post of observations, not a thread about everyone else's observations. Like every other person's post on this forum, it's just my opinion, and everybody here has them. Like you, some I appreciate, and some I don't. But I enjoy it all.

Well, you might want to factor in that while Mr. Whidden’s information is , no doubt , helpful to many and always interesting, he is fairly new at the game with limited numbers by which to make observations, not to diminish his info.
Some, have been testing, selecting, competing, and using test centers for literally decades.
Some of those observations have over the span of time, become well established facts and easily verifiable with a bit of effort.

 

[Tad_Earhart]

Nobody is talking about older sporters or tapered barrels which are rarely seen on BR platforms. BR around 7/8? Not much.
the vast majority of BR barrels fall between .875”- .920” with most of those around .900 and that has been the case since the early 1990’s.
This, all for true RFBR platforms.

7/8" = 0.875"

 

[whiddengunworks]

ATFIV I think that lower muzzle pressure may help the accuracy some, but have no solid data on this. I don't think it's readily something we could test. I expect we'd need to shoot an ammo with a certain velocity and then make some of the same ammo with a reduced velocity and hence reduced muzzle pressure. Unfortunately we're not equipped to do this well.

Ranger188 I have not done any measuring or selection of ammo but just take it out of the package and shoot it. No data on that yet. This is without data, but it appears that headspace doesn't have much effect on accuracy, as long as it's in a range where the firing pin strike is good to go.

TSR8 we're pretty new to testing but I'm hardly new to test centers, competing, and decades of it all. ...and we shot about 36,000 rounds last month in the test range. I'll still gladly admit that we all have a lot left to learn.

 

[flatlander]

Jeez-o-Pete! 36k rds in a month?!? No wonder the guys who work the Lapua Test Centers get burnt-out & move on to other jobs.... I would love to have access to a really well-constructed test tunnel so I could work with the tuners on my 22s whenever I had the time, instead of being so dependent on the weather.

 

[TRSR8]

ATFIV I think that lower muzzle pressure may help the accuracy some, but have no solid data on this. I don't think it's readily something we could test. I expect we'd need to shoot an ammo with a certain velocity and then make some of the same ammo with a reduced velocity and hence reduced muzzle pressure. Unfortunately we're not equipped to do this well.

Ranger188 I have not done any measuring or selection of ammo but just take it out of the package and shoot it. No data on that yet. This is without data, but it appears that headspace doesn't have much effect on accuracy, as long as it's in a range where the firing pin strike is good to go.

TSR8 we're pretty new to testing but I'm hardly new to test centers, competing, and decades of it all. ...and we shot about 36,000 rounds last month in the test range. I'll still gladly admit that we all have a lot left to learn.

Thanks, understood.
My primary point, which I suspect that you’d agree, the process, procedure, etc. Has been around some time with many areas well understood, not to diminish your efforts.
My hope, as well as many others, is that your info provides encouraging data relative to ELEY, be nice to have them back in the game to a larger degree.

 

[Rsadams]

Regarding your findings on barrel fouling, I also found this out with my Anschutz 1710 HB. From a squeaky clean bore it took only 3 rounds for full accuracy and true POI to return. I have read some state 20 or more rounds to settle in but I just haven't seen that.

Exactly what I have seen , normally at about three rounds the new ammo takes affect over the old and I have been told one shot per inch of barrel to foul it properly and get the wax in the barrel... Today I shot about ten and it was normal again after a serious clean down to bare metal and like normal about five shots after changing ammo and it's good to go with the different ammo....

 

[TRSR8]

7/8" = 0.875"

“ with most of those around .900”.
Read the whole sentence there sport.

 

[tactserv]

With this question much depends on what is believed.

Some explanations of how tuners do what the do assert that positive compensation explains how tuners work to put rounds of different MVs in a very similar POI. The positive compensation theory says that the tuner does its job by timing the barrel vibrations so that slower rounds exit the muzzle with a higher trajectory than faster rounds. This allows them to have a POI similar to faster rounds.

If positive compensation is correct it would mean that tuners settings work for one distance, not all distances.

For more on positive compensation, see these two well-known explanations.

Using barrel vibrations to tune a barrel

22 Long Rifle Barrel Tuner Analysis -- FEA Dynamic Analysis of Esten's 22LR Rifle with/without a Tuner.

Of course there's no agreement about how tuners work. Others subscribe to the idea that the tuner works to "stop" the muzzle from moving by tuner adjustments causing a "vibration node" to be at the muzzle. An explanation such as this seems to allow tuners to work at any distance reasonable for .22LR.

I sorta disagree. Understanding how/why tuners work falls into the 'nice to know' category, best left for libations after the match. The fact that they work is easily demonstrated, and adjusting them for best effect on an individual rifle is (or was for me) a fairly straight forward exercise. I used the Hopewell Method. Uses bunches of bullets, but when I repeated it a week later (same ammo lot) I arrived 1 setting off from the first time I did it. Humorous note: After I landed on setting best for my rifle/tuner/ammo setup, I found another fellow who was expounding on tuners, and he said just set it on 250 and shoot it. My setting? You guessed it, 250. I do think tuners have more effect on longer, slimmer barrels. Look at most purpose built rimfire benchrest guns: ~26" length, .90" diameter barrels. What I really mean to say is, set your tuner at mid-point, ammo lot test for smallest horizontal spread, and adjust tuner for smallest vertical spread. JMHO, YMMV.

 

[CharlieNC]

I sorta disagree. Understanding how/why tuners work falls into the 'nice to know' category, best left for libations after the match. The fact that they work is easily demonstrated, and adjusting them for best effect on an individual rifle is (or was for me) a fairly straight forward exercise. I used the Hopewell Method. Uses bunches of bullets, but when I repeated it a week later (same ammo lot) I arrived 1 setting off from the first time I did it. Humorous note: After I landed on setting best for my rifle/tuner/ammo setup, I found another fellow who was expounding on tuners, and he said just set it on 250 and shoot it. My setting? You guessed it, 250. I do think tuners have more effect on longer, slimmer barrels. Look at most purpose built rimfire benchrest guns: ~26" length, .90" diameter barrels. What I really mean to say is, set your tuner at mid-point, ammo lot test for smallest horizontal spread, and adjust tuner for smallest vertical spread. JMHO, YMMV.

I sorta sorta disagree too. The more you understand how something works means the better you can effectively utilize it's capabilities.

 

[TRSR8]

Tuners work. Do we know “exactly” how? Probably not. Myself, I don’t really care, but they work and setting them up is pretty straight forward, the big controversy is whether to constantly twist them and /or hang all manner of crap on them but, alas, RFBR shooters often seem to make things far more complicated than they need to be rather than working on skills.

 

[MarkS]

I've been away at a match for a few days "Living My Best Life" as my kids say.

Concerning cleaning we have no real data. My own experience is that it's highly barrel dependent. I have one that shoots quite well then fouls out between 350-400 rounds. Eley has us clean after we test 15 lots x 10 rounds so 150 rounds total. We clean quite thoroughly with Iosso when we do clean. We do not see a deterioration in accuracy over 150 rounds. If we did, then we'd never see the last lots we test shoot well.

About the tuner, I hope to rerun that test that gave me different tunes for 50M and 100M. I have shot that rifle from the sling since that test, and my own sense is that the two different tunes do indeed hold up in the outside world. We will have an opportunity to test this again at some point.

If barrel diameters matter, it's not obvious to us at this point.

Thanks for your reports from the test range. I am a long range rimfire steel shooter, not a BR guy. I use EC V2 tuners on my guns. I can see 50M and 100M having different tune due to the ES of ammo. It want be a lot, but it will be there. The farther you go out the more vertical you will see. I start my tuner at 50yds, then take the best groups to 200yds to fine tune, moving 2 marks at a time, each way. You can tune the vertical out of the groups. I had Very good not wind condition one day, and did some tuning at 400yds.

 

[Hi-NV Shooter]

Tuners work. Do we know “exactly” how? Probably not. Myself, I don’t really care, but they work and setting them up is pretty straight forward, the big controversy is whether to constantly twist them and /or hang all manner of crap on them but, alas, RFBR shooters often seem to make things far more complicated than they need to be rather than working on skills.

Tim, you know how they work. just go look at one of your sporters

 

[TRSR8]

Tim, you know how they work. just go look at one of your sporters

Well…..there’s that.