New to using a 'PEEP & GLOBE' at 50 yards...

[303Guy]

I must confess I had assumed the lateral harmonics would be similar to the vertical. Well, they would be different because of the mounting of the barreled action. Even so, I would have expected the X and Y axis to be similar.

[dverna]

Wow, that air gun tuner is impressive. I bet it costs as much or more than my last PCP rifle!

If I ever go down that path I would spend some time on my little lathe and make something. It does not look like rocket science but I may be missing something. The hole for the bullet to exit it not critical so it can be large to avoid "cllipping". All the tuner does is add weight to modify the harmonics and it has a way to track the settings as to how far the weight is positioned. Seems like a lot of money for what it does...but like I said...I may be missing something.

[tazman]

Wow, that air gun tuner is impressive. I bet it costs as much or more than my last PCP rifle!

If I ever go down that path I would spend some time on my little lathe and make something. It does not look like rocket science but I may be missing something. The hole for the bullet to exit it not critical so it can be large to avoid "cllipping". All the tuner does is add weight to modify the harmonics and it has a way to track the settings as to how far the weight is positioned. Seems like a lot of money for what it does...but like I said...I may be missing something.

Look up the "Purdy Prescription" as it pertains to rifle accuracy. He did a food bit of research into barrel harmonics and stabilization.

[tazman]

I hope OS is OK. He said that he was planning on doing some shooting yesterday and I am interested in seeing what happened.

[uscra112]

Clear and colored apertures:

https://freelandssports.com/product-...hts/apertures/

[dverna]

Look up the "Purdy Prescription" as it pertains to rifle accuracy. He did a food bit of research into barrel harmonics and stabilization.

Thanks for posting that. The most current stuff I found on it was posted in 2018. Not sure what that means wrt how much acceptance the "prescription" still has, but the early postings were very positive. The guy seems to have found something useful.

I wonder if OS OK could use the information to help determine his tuner setting.

As to addressing my questions, it would seem to confirm that any means of changing the harmonics of the barrel will work...mass and length past the muzzle...one type of tuner does not seem to be better than another. Interestingly, none of the formulae took into account the velocity of the ammunition. Whether that is due to the consistency of "match" ammo (that is all under the speed of sound), thereby making it a minor influence....or the node is not affected by a difference of say 100-200 fps. My gut tells me velocity will make a difference so it leaves me puzzled. Some of the stuff I have read mentions barrel time. Yet, if the there is a harmonic length that produces a node independent of barrel time, velocity will have no affect.

[tazman]

The Purdy prescription was also used in air rifles. In order to get it to work there, they needed to use a different harmonic due to changes in velocity.
I read it last night on one of the air rifle forums but don't remember which one or how I got there. Sorry.
I think your idea about this working due to the very similar velocities of match ammunition is correct.
I expect significantly faster velocity would definitely make a difference. Just how much, I have no idea.
I know the man who developed this, left his email address on several of the forums and welcomed questions about it's use and was willing to help people work through issues.
I have no idea if he still does this.

[OS OK]

Oh...I'm OK...just been down the Rabbit Hole with some odd results that I can't explain...been trying to get a single morning of testing where I had a good 30 minute 'lull in the wind'.
The other day I needed a '50 yard fix' so I shot anyway...dang the wind! It wasn't pretty.
It's been so hot lately that the morning wind just turns around almost immediately and increases.

I did my warmers & sight adjustment on another sheet so I wouldn't clutter the small test I wanted to see...



One thing I wanted to mention is the last 5 yards before the backstop is not blocked by the house. For some reason there's always a strong & steady wind there when the day is gusty/unstable, this morning it was steady around 4 mph. Many times I notice the streamer on the backstop in opposition to the other two wind flags. I thought this may be influencing the results but in 5 yards I want to seriously doubt it.



Conditions weren't good this past week. It is difficult to try to wait the gusty wind out, I think the barrel cools what little heat it gains and I am getting unexplained fliers.
They resemble that first shot of the warmers group...



From looking at the other tests so far, I think the barrel tuner is trying to show me that 'flush' with the muzzle is where it is going to perform. I set it to '-1/16" because the crown is inset from the end of the barrel by that amount.
Here's the latest & like I said..."it ain't pretty" so I'm trying not to get any ideas about this that are unfounded...



I wasn't waiting on lulls, I was shooting on anything less than 2 mph...target 12 is the only target where the wind actually remained at the 2 mph for all 5 shots, that's why I noted it there. That condition did not happen again.

About the fliers...
Spot #1, there was a few minutes that passed between the other warmer & sight adjustment card...I thought that first shot was from a cooled barrel.
Spot #13, by this spot I had been shooting in a smooth & repeatable sequence, no long waits between shots or spots, just shooting and trying to get consecutive data. On this spot I shot the 'X' on the first round, I shot the 7:00, 7-ring shot next. Then...the numbered shots 1 ~ 3 came in succession. BIG FLIERS! That really confused me & then...
Spot #15, the shot numbered 4 was the first shot there, another big flier! After that they settled right back to the loose groupings...

You will notice I used Contact, then Match & then Contact again consecutively without any barrel swab or dry patch. Both ammo's are lubed with the same parraffin so I didn't think this would matter, only the speed and the shape of the projectile were different.

Spot's #21, 22 & 'maybe' 23 have that first shot flier also. There was no pause in timing of those shots, no barrel cooling (if that could make a difference). This is what I can't get a handle on?

Harry Tobin called later in the morning and we talked about this. Harry thought that it just may be that poor looking bushing I made from the wound brass shim stock.
Brass is not exactly a lively metal after I annealed it, it is soft and Harry thinks it is unable to carry the harmonics from the steel barrel to the tuner efficiently. Harry offered to make me a proper bushing on his lathe when he gets the time. Harry is swamped with 'honeydoo's' and work and all the rain he is getting is screwing up both.
Anyway...today I'll head out and find a 6" long x 1" OD piece of cold rolled round stock and I'll mail that to Harry along with another scope ring from the set I have currently on the barrel.
Until I get to this next step of installing a proper & 'lively steel' bushing, I am going to let this MKII take a rest. I will go back to the CZ452 and enoy that rifle for a while.

PS...sorry for not commenting on the above posts and that purdy's prescription...I just haven't had the room in my little pea'brain to consider anything but the problems at hand. Don't think I am ignoring anyone, please...you fellas know by now that when I get into a tail-spin I have to work it out or go bust!

[dverna]

Charlie,

First, 5 yards of wind influence will have little effect so do not sweat it.

As to the "bushing", why not let one side of the scope ring bear directly on the barrel and use your filler (brass sheets or whatever) to build up the other side of the scope mount. I doubt there will be any movement with .22 recoil. Easy enough to try and no waiting.

[tazman]

Charlie,

First, 5 yards of wind influence will have little effect so do not sweat it.

As to the "bushing", why not let one side of the scope ring bear directly on the barrel and use your filler (brass sheets or whatever) to build up the other side of the scope mount. I doubt there will be any movement with .22 recoil. Easy enough to try and no waiting.

Good idea! I would suggest putting the material on the top so the bottom would be in direct contact with the ring metal. Any vibration would transmit easily to the torpedo.

[OS OK]

Charlie,

First, 5 yards of wind influence will have little effect so do not sweat it.

As to the "bushing", why not let one side of the scope ring bear directly on the barrel and use your filler (brass sheets or whatever) to build up the other side of the scope mount. I doubt there will be any movement with .22 recoil. Easy enough to try and no waiting.

Good idea! I would suggest putting the material on the top so the bottom would be in direct contact with the ring metal. Any vibration would transmit easily to the torpedo.

Thanks fellas... I didn't have any idea about that last 5 yards, the wind there sorta slides off the side of the house like wind on a sail. It can be significantly stronger at times.

In my mind, that bushing has to be perfect all the way around the barrel. A tight non slip fit.
One reason is I want to stop any torque that would tend to twist that tuner to the side like I saw early on...



I want to transmit all that energy to the tuner's mercury. You can see the twist in the picture above.

Second reason is that I want all the vibrations to transmit directly into the tuner...I don't want anything between barrel and tuner that would tend to absorb the shock by only a percentage. I can see in my mind's eye what I think is going on with the mercury...I think it makes little waves in every direction...hmmm...not sure I can explain this other than it would look like the surface of a calm lake when a severe hailstorm hits...the surface just turns to a froth absorbing all that energy.

I bought the 1" round stock this morning and got that and the other scope ring off to Harry a little earlier today. It won't be long and we'll be back looking at this tuner. This time a complete tuner with no 1/2 measures. It's going to work or it will fail on it's own merit...no more wasted ammo.
The only other modification I can think of is adjusting the volume of mercury but I can't see that being necessary as when it's 1/2 full it has the largest absorbent surface area, I think the length it is set in relation to the muzzle has already shown itself.

Be patient, it's hard for me too but we are going to get there soon.

[tazman]

Keep in mind, it may not be the vibration transmitted but the actual weight of the mercury or both, that is doing the job. I don't know for sure either way.
When you get the torpedo mounted solidly, like you want it, and have tested it to see what it does, test the setup with more weight of mercury and see what happens. Even fill the tube completely and try that. It may make no difference or a lot.
No way to know without testing.

[OS OK]

hahaaa tazman... we think a lot alike!

Just because we get this thing working, you don't think I'm gonna quit there do'Ya? A true 'tinker'er' never can let 'good enough' alone!

I went to bed last night thinking of trying it on the CZ452. (if it works out on the MKII of course) I was trying to remember the barrel size and what bushing I'd need for that.

[tazman]

The thing is, we have more than a single cause for vibration and movement when firing a gun.
We have the explosion of the powder, the movement of the bullet, the expanding gasses, the sudden release of the gasses, and the recoil of the firearm to consider as well as anything our physical contact with the gun may introduce.
Some of these will certainly be more dominant than others, but they are there. Lots of stuff working together and against each other to cause lots of movement, however small.
It only takes .005" of movement at the muzzle to move the bullet a quarter of an inch at 50 yards and that doesn't even take into account any possible flexing/bending of the barrel.

[OS OK]

The thing is, we have more than a single cause for vibration and movement when firing a gun.
We have the explosion of the powder, the movement of the bullet, the expanding gasses, the sudden release of the gasses, and the recoil of the firearm to consider as well as anything our physical contact with the gun may introduce.
Some of these will certainly be more dominant than others, but they are there. Lots of stuff working together and against each other to cause lots of movement, however small.
It only takes .005" of movement at the muzzle to move the bullet a quarter of an inch at 50 yards and that doesn't even take into account any possible flexing/bending of the barrel.

Actually taz... the vibrations start when the sear lets loose, minuscule vibrations start radiating out in every direction & down the barrel to the muzzle, from there they start reflecting back up the barrel towards the source.
At the same fraction of a micro-second other vibrations you describe are adding to the transmition coming from the receiver and doing the same thing. In the barrel and receiver all those vibrations are either adding in amplitude or canceling each other to some extent...maybe I shouldn't say that because it will confuse the issue but that barrel is no different than an antennae that radiates electrical vibrations in magnetic pulses. As the frequencies run down the antennae feed line and antennae itself, those reflected frequencies are a problem, they reduce the efficiency of transmition. In the barrel they essentially add to the barrels reaction...
This does and doesn't have anything to do with the harmonics in a barrel other than we are essentially dealing with the same thing...it's just harder to measure, harder to visualize.

The other day when I was describing what I think is going on in the Mercury filled Torpedo..."I can see in my mind's eye what I think is going on with the mercury...I think it makes little waves in every direction...hmmm...not sure I can explain this other than it would look like the surface of a calm lake when a severe hailstorm hits...the surface just turns to a froth absorbing all that energy."
This is what I am describing...



This is the surface of a water filled glass just prior to the glass breaking from a very strong transmition of the resonate frequency of the glass...something akin to the barrel harmonics. The water is absorbing those frequencies & reacting...I think of this as a shock absorber of sorts. It is using up the power of the harmonics/in this case sound frequency. This is what I have in mind with the Torpedo Tuner and it's mercury inside.

You can't imagine how much I would enjoy a high speed camera to film the reactions of a barrel as the sear lets loose and starts the chain reaction of harmonics...we would see exactly the muzzle's reaction start to finish, very much like we see the shattering glass in the video below...

Remember as you watch...that glass is a hard object just as the barrel is hard...yet it flexes in shape, who would'a thought?



Well, I'm up late, can't sleep...the brain won't stop...thought I'd share this in hopes of giving some of the followers of this thread something to think about, at least give them a picture of what I have been having a hard time describing.

Harry Tobin has already completed my barrel bushing and it is in the mail heading for the Left Coast.



I swear, I don't know how this thread could have gone this far without Harry's attention and help. "Harry, you are a pretty swell fella, thank you ever so much for all you have done to help me!"

When these bushings are installed, I think we will see this tuner work or fail...I am betting it works even better than it has already...those bushings will transmit all the vibrations, all the harmonics of the barrel into the Mercury. The only question I have now? How much vibration/harmonics can that mercury absorb? Will there be enough of it?

[tazman]

People always use analogies to things they are, at least, somewhat familiar with. I shot Olympic style archery competitively for over 14 years until I tore the connective tissue in my shoulder. Recurve bows and finger release. At one time, I could shoot smaller groups at 20 yards with my bow than I could offhand with a rifle. Definitely better than with a handgun.
We used stabilizers to dampen the vibrations in the equipment. Some of them worked really well. Some were hydraulic. A very few used mercury. Many were combinations of metal and weights. Some did little except change the balance of the system.
There are some likenesses between the ideas used and some of the techniques being used for rifle shooting. Some don't apply at all.
I get some of my ideas from the things we used in archery. The preferred outcomes are very similar.

[OS OK]

People always use analogies to things they are, at least, somewhat familiar with. I shot Olympic style archery competitively for over 14 years until I tore the connective tissue in my shoulder. Recurve bows and finger release. At one time, I could shoot smaller groups at 20 yards with my bow than I could offhand with a rifle. Definitely better than with a handgun.
We used stabilizers to dampen the vibrations in the equipment. Some of them worked really well. Some were hydraulic. A very few used mercury. Many were combinations of metal and weights. Some did little except change the balance of the system.
There are some likenesses between the ideas used and some of the techniques being used for rifle shooting. Some don't apply at all.
I get some of my ideas from the things we used in archery. The preferred outcomes are very similar.

We both have similar backgrounds tazman... I started off with indoor competitions & there we had access to a high speed camera but in 1978 they weren't what we have today. Amazing how that arrow takes the horsepower of the limbs and immediately turns into a sine-wave and swims towards the target.
From there I enjoyed outdoor marked ranges for a couple years until the first 3-D 'unmarked yardage' shoots began with life size 3-Dimentional animals. This completely captivated me and several of us started experimenting with making our bows real high speed shooters. We changed everything, spline & length & started using overdraw rests in search of that high speed arrow that had minimum arc in it's flight path to compensate for our in-expertise at judging distance. No rangefinders were allowed but eventually we discovered how to use our pins to estimate distance. Gosh...that was a fine hobby, I look back and it makes me smile today...still have all my bows.

Here's another video in slo-motion, this is terrific. How I wish it was about .22lr bench rest instead of cannons but you can still see so much in this video that would remind you of a rifle...the flex of the carriage vs the flex of our stocks, the exit of the round and fireball & the pressure waves, don't miss this video.

[tazman]

After my shoulder healed, my doctor told me I could shoot a compound and release since the strain on the shoulder was using different tendons. I wasn't certain how he knew this but he was right. I switched to compound with release and shot for another ten years in field, indoors, and 3D. I got very good at guessing yardage.
Since I could guess the yardage, I went for maximum accuracy with speed, not just how fast it could go. My setup was running about 285fps and I could shoot 300 with 50-54 X on an indoor target with it. Made a great system for me. I was constantly accused of cheating except by the people who shot with me. I always went around the range with members from the club where the range was located to avoid issues.
Several times, I had people stand up for me to the point they were going to fight the accuser when someone claimed I could not have shot the score I did.

Some of those stabilizers we used were very simple. A small piece of metal bound somehow by a piece of rubber. They seemed to work well enough in taking the vibration out of the bow.
Some were pistons inside a tube filled with hydraulic fluid of some type.

[tazman]

Another thought rolled through my head today. Since you have the ring so it will soon fit the barrel tightly, make up a lead weight, or series of different weights that can be attached to the clamp of the ring. This might tell you if it is the mercury or the weight that is doing the job.
Lead, by itself, dampens and absorbs vibrations on it's own.

[OS OK]

HARRY TOBIN CREATIONS... came through again first class. Harry is really Backyard Inventor ( https://www.youtube.com/channel/UCwe...pdFTsXw/videos ) on the YouTube, I just hung that name on him since he has created so many things to help me out in both these threads I have been running. Thank You Harry!

I thought I'd have at least a couple weeks to play with the CZ452 before coming back to this thread to work further with the Torpedo...not so.
With this bushing, I'll have as solid of a coupling as I can possibly have now to the barrel.



Harry even 'cold blued' the bushing...man what quality work!



Centering the scope ring on the bushing, the ring is about 3/16" farther back on the barrel so I will re-black the rail and put a new scale on it so I can start with new testing with the Torpedo flush mounted to the crown of the barrel.



We will see some test in about 6 hours providing I have that morning lull in the wind this morning.