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

[Harry Tobin]

Dang looks like a grenade launcher

[tazman]

That last five shot group was great. Looks like you are onto something. Next will be different amounts of mercury in the tube to see if that matters.
At least you have a substantial amount of ammo to test it with.

[303Guy]

Yeah, I've been a little distracted lately. I did manage to get to the range on Sunday. Awesome weather! Heavy frost, cool crisp clear air. Clear blue sky.

At one point while I was waiting for something, I was watching this fellow shooting his 22. I was shocked at the recoil! I mean, it was visible. That made me realize why it is so important to hold a rifle consistently just so. I had been having the POI shifting. I shot a six shot one hole group (my first - I'll be framing it) and the next group opened and moved! Obviously I was holding the rifle differently. I wasn't too with it on Sunday, just having had my first covid vax the day before and was feeling a little light headed.

Anyway, what's important is the outcome of your CO2 bottle damper. I'm thinking of long weight either rigidly clamped on or clamped via hard rubber. That scope ring idea could be adapted to my purpose. Oh, I have an identical set of scope rings. I haven't seen those around for a long time.

[OS OK]

Yeah, I've been a little distracted lately. I did manage to get to the range on Sunday. Awesome weather! Heavy frost, cool crisp clear air. Clear blue sky.

At one point while I was waiting for something, I was watching this fellow shooting his 22. I was shocked at the recoil! I mean, it was visible. That made me realize why it is so important to hold a rifle consistently just so. I had been having the POI shifting. I shot a six shot one hole group (my first - I'll be framing it) and the next group opened and moved! Obviously I was holding the rifle differently. I wasn't too with it on Sunday, just having had my first covid vax the day before and was feeling a little light headed.

Anyway, what's important is the outcome of your CO2 bottle damper. I'm thinking of long weight either rigidly clamped on or clamped via hard rubber. That scope ring idea could be adapted to my purpose. Oh, I have an identical set of scope rings. I haven't seen those around for a long time.

Here's a 'mid-barrel' one I saw when looking for ideas for mine...this sounds like what your describing?



I hope your Covid shot goes well in the future...people over here are having real problems with the jab. I ain't gonna do it!

[OS OK]

New day...better testing... I put some 1/8" temporary scribe marks on it so I could come back to one if it looks promising. I wanted to extend it out to 1/2" but a little weld bugger blocked the track (need to grind the underside of the channel where that weld is too wide)...I could only extend it out by 7/16" max.





The testing was 5 spots each of 2-shot groups, starting at flush with the muzzle and extending it out 1/8" each 5 groups. This is a rather cursory look at potential nodes...if I was using the Harrol tuner...this would be skipping 125 settings between spot samples. I didn't figure I would need such close adjustments anyway since the Mercury is the main thing in this tuner.
Anyway...here they are...



I thought the 'flush setting' was the most promising so I did 2 ea. 5-shot proof groups up on the top next to the warmer spot. That first one looks something like 3/16" (?) that impressed the heck out of me. Well...until I tried the second group...man that went south quick. I wish I would have had more spots open to try that 5-shot group again.
I guess I should use a different card for all the 'potential nodes' testing.

All those green marks are where the tuner had no control whatsoever...these 'fliers' just took off but it's curious that all the fliers of the day headed out of group in the same direction.
Spot no.3's first shot was bizarre so I added another shot to make it a 2-shot group (that first shot resembled the first shot of the warmer group.) I watched that shot heading for the spot, looked like a downhill skier...it went out a little ways and headed straight down.
Like a dummy, I didn't bring the chrony out so I am at a loss to explain those shots highlighted green. It wasn't me, I had no called shots/fliers...I did my part.
That ammo came out with an ES of 70 & SD of 16 the other day & the next time over the crony was pitiful also...ES of 68 & SD of 13.
So far I think this tuner is making that crappy ammo really shine.

When I got back to the shop to study this card, I scribed the tuner with marks that would allow me to go shorter than 'flush with the muzzle' in 1/8" increments. Tomorrow I'll do another test like this and see what the short side looks like. This time I'll bring the crony out too so we can get some idea about these weird fliers?



Conditions today...



In the top picture you can see the 1/2" x 1/8" wide neoprene rubber I used for a scope ring shim. I am not happy with this, I wanted a solid connection to the barrel (metal to metal connection) so all vibrations went directly to the Mercury...this rubber shim, I think is buffering those vibrations and not allowing all of them to reach the Mercury without having a buffer of any sort in-between.
Harry Tobin and I were talking about this and searching the McMaster Carr catalogue on line for bushings of the correct size made of metal, no soap! Didn't find anything that'd do...so I am going to use a ring cut from a copper sweat fitting for 3/4 pipe, cut it off the width of the scope rings, slit it and hammer it down to size to fit the barrel. I'll have to make this bushing in two pieces. This is what I wanted from the start.

[303Guy]

Thanks, OS. I'm not feeling too great today, nor did I feel great yesterday but the day before was fine. It could be something else of course.

The thought that entered my mind was to mount those rings on each end of a heavy walled tube, placing the barrel in the center of said tube. I know, I know, I get these strange ideas! Thing is, scope rings are a great way to mount things and it wouldn't take much to mount them on each end of a tube. I have a lathe so I can do things like that fairly easily. Including making hard rubber or plastic adaptor bushes. Anyway, I'll see which way I go.

[tazman]

Didn't your CZ452 originally have some lead weights attached to either the tuner or barrel?
Might try something like that on this rifle as well.

[OS OK]

Thanks, OS. I'm not feeling too great today, nor did I feel great yesterday but the day before was fine. It could be something else of course.

The thought that entered my mind was to mount those rings on each end of a heavy walled tube, placing the barrel in the center of said tube. I know, I know, I get these strange ideas! Thing is, scope rings are a great way to mount things and it wouldn't take much to mount them on each end of a tube. I have a lathe so I can do things like that fairly easily. Including making hard rubber or plastic adaptor bushes. Anyway, I'll see which way I go.

I think the idea behind that tuner I posted was to be able to adjust the bar as the forward weight & it looks strangely like a tuning fork too. The whole idea is to have a tuner that fools the barrel into re-acting longer than it is and make the natural node come forward to the muzzle. Without anything on the barrel the node supposedly is 1.5" behind the muzzle.
I am hoping the Mercury is a vibration eater. A one way dump that the harmonics can't bounce back from.
I hope you are not having a reaction and it's really something else...charlie...I'll include you in my prayers tonight.

Didn't your CZ452 originally have some lead weights attached to either the tuner or barrel?
Might try something like that on this rifle as well.

Yes, it had stick-on weights that were all in a parallel row together and they wrapped the tuner 360º. I have a long ways to go before I give up on this deal just yet.
Those lead weights looked like a tank muzzle...pretty funky.

[tazman]

Why I was thinking about those weights.
I was watching some videos of biathlon rifles and took some close looks at the muzzles. Nearly all had either an enlarged section in the last couple of inches at the muzzle or had some kind of weight with a front sight incorporated into it. Basically added weight to the end of the barrel.
I understand the need for as little weight for the athlete to carry as possible, so why put weight on the end of the barrel unless it serves some purpose?
I am thinking the weight itself, acts as a stabilizer and dampens the oscillations of the barrel somewhat. Somewhat like a tuner but not as precise, perhaps.
Just something else to think about.
I don't know enough about barrel design.

[OS OK]

Why I was thinking about those weights.
I was watching some videos of biathlon rifles and took some close looks at the muzzles. Nearly all had either an enlarged section in the last couple of inches at the muzzle or had some kind of weight with a front sight incorporated into it. Basically added weight to the end of the barrel.
I understand the need for as little weight for the athlete to carry as possible, so why put weight on the end of the barrel unless it serves some purpose?
I am thinking the weight itself, acts as a stabilizer and dampens the oscillations of the barrel somewhat. Somewhat like a tuner but not as precise, perhaps.
Just something else to think about.
I don't know enough about barrel design.

In my simple reasoning taz...I believe it's the gross weight of the end of the barrel trying to resist initial movement by the shock waves. Remember the physics thing about motion?
Things at rest tend to stay at rest & things in motion tend to stay in motion.

I think in their adding weight to the barrel, buys them more time for the round to clear the muzzle before the barrel actually succumbs to the 'building/increasing' harmonic waves and starts into it's gyrations.
Not by beating the vibrations/shock waves to the muzzle, but slowing their net effect at the muzzle until that round can get out of bore before the gyrations become more amplified and to the extreme....causing the POA of the bore to change wildly.

This is a good read about this and more waves that travel that barrel at near light speed but when they start in with their computer predictions, they sorta loose my attention. I like the discussions of that which has been photographed or recorded in some way regarding barrel movement. Yes all the calculations are of primary importance, I agree but the numbers are not as exciting as seeing it happen.

Barrel Harmonics, Pressures and Timing
https://www.shootingsoftware.com/barrel.htm

This next link is one of many he has under various titles, what I like here is the animated movie clips that explain what their computer simulations suggest. I have a KISS Brain (literally!)
Varmint Al's page
http://varmintal.comwww.varmintal.com/amode.htm


This is a subject for the truly gifted in mathematics & computer simulations guys...as a typical 'RedNeck Shade Tree Engineer' I think I am merely 'muddling in the dark' but I adhere to the old axiom...'try it or you'll never know' bunch.

PS... going to try to get another card shot today with the Torpedo set behind the muzzle.

[303Guy]

Thanks, OS. Today I am feeling much better.

I'm thinking there are two beneficial effects of a weight at the end of the barrel, one being to slow and dampen the movement of the muzzle and the second is to stabilize the rifle off hand hold.

I once fitted a small moderator device onto a long and skinny barreled 25/303 Lee Enfield. This thing shot sub-MOA at 200 yds! Of course I didn't keep the target! I had a photo of it but lost that when my hard drive died. I thought at the time it was simply barrel dampening and that I accidently happened to get the weight and its position just right.

[OS OK]

Tuning on the short side...of the muzzle yesterday morning, in 1/8" increments again but this time I have the chrony out in front. I had intended to plot every shot and get some idea about those low fliers from the other day...
average conditions for the day (notice the temperature in the sun...105ºƒ) I am shooting from the comfort of the umbrella at 80º...from the front of the scope to the tuner, it's all in the sun the whole time. More on that later...



Both cards side by side. I chose to shoot the flush setting again & from this card the -1/8" setting.



Here's a better view of the 2-shot 'Pre-node Search'...there's a lot of information here, I sat like a deer caught in the headlights staring at this card. I'm thinking I should have the answer to those pesky low fliers...they don't make any sense.
I couldn't come up with even one 'spitwad of an answer'...



First thing I looked for was the shots being segregated by speed, by fps....thinking the faster the projectile, the quicker it leaves the muzzle therefore they will be...either above or below the slower ones, depends on how the barrel has flexed at that point in time but it should show a pattern here...I don't think it did...?

Then I shot the 'Proof Node Card', choosing the flush & the -1/8" settings...no time out between the two cards other than re-setting the chrony & the tuner to flush and getting back in position. Not more than a couple or three minutes.
Then the bottom fell out...meaning 'everything went to heck in a hand basket'.
I was stunned to see these results..."Obviously something has come loose, there has to be an answer to this & that will be easy to locate."



Both node settings showed good 2-shot potential and we should have seen much better groups here...but didn't.
Then it became obvious...or at least in my thinking it was. That neoprene band I used for a bushing between the scope ring (.960" ID) and the barrel (.800" OD) has to be heating up from the sunlight and becoming softer & allowing more flex in that application as a bushing. That's all I had to go on...this has to be the answer...me thinks?

This I came up with after going back in the shop, I had checked all the screws...scope mounts & all the way down to the stock screws and pillar mounts. I cracked the action from the stock and checked everything there...nothing to be found suspicious. That's when I decided it has to be the mounting of the tuner...me hopes?
I removed the tuner, carefully measured the dimensions and searched the shop high & low for something I could fashion into a good bushing. A metal to metal bushing that will not flex...a bushing that will transfer all the harmonic waves directly to the Mercury filled (1/2 full) Co2 cartridge.

I finally decided that without a lathe I can't make a proper bushing, not even close.
At this point all I have is a 6" wide roll of brass .010" shim stock. I pulled out about 16" and cut it off, then cut a strip of shim stock that was 3/4" x 16".
Next was to anneal it soft as I can get it...take all the spring from the material and carefully wind that stock onto the barrel until I get a +.080" thick winding that would measure about .980" OD.
It took a couple attempts to keep it tight as possible, I needed an extra hand in the worse way...but I got it.
I tightened the scope ring really tight, close to the stripping of the threads. I didn't have that little torque wrench, it's due here sometime today but that connection now is a good one, metal to metal and I can't make that tuner wiggle on it's mount.
It doesn't look very professional, I couldn't keep that winding all stacked evenly on the sides so it would look like a bushing but it is solid as a rock now...





Now it's back to the 50 yard line and 'punt again'! More testing on it's way. This time just the 5-shot proof groups...'flush & +1/8" & -1/8"' to start out, I think a good node will be found between those settings.
Remember, take another look at all the Average fps & ES & SD's up on these cards...this is lousy 'minute of tin can' ammo...already I think I have seen this tuner doing wonders for this ammo's capabillity...that's a subjective observation though.

[dverna]

The brass "wound bushing" should do the job...good thinking.

Another option, if it does not, is to use JB weld with plenty of release agent on the barrel and mount.

[303Guy]

I was thinking of epoxy if all else fails too. My go-to is Knead-It. Hard as nails but softens nicely with heat. Thinking about that stuff, I got clever one day and used it to bed my hornet. Well, the release agent didn't release! But when I need to take it off, I can simply use a hair dryer. Another trick where clearances are small is paper or card. It does need to be solidly clamped though to compress it to the point that it can't give. But anyway, the brass shim stock trick is probably the best idea there is.

[OS OK]

Thanks for the heads up on epoxies fellas...I believe that I am good to go with this shim-stock. Wanted to proof shoot those settings this morning but I worked in the East Pasture from sun-up to about 0800 finishing up the Star Thistle removal. I got it done...thank GOD above!

By the time I got back to the shop the wind was still but starting to move some, coming back up from the valley below. When it turns like that, it's only a matter of minutes before it starts blowing. I thought 'what the heck'...I have to see something with this hard-mount...to heck with the wind.
Here's a limited selection of Proof Spots, all the details are on the Card...when I changed to the Eley Match at the bottom of the card, there was about a 15 minute pause in the shooting...I think the barrel cooled and caused the errant shots, I don't think it was the lube as Contact and Match both are lubed with paraffin.



You'll notice that at the bottom I switched to Eley Match wanting to see what a better ammo might do. The wind was part of it all but I think the 'Torpedo' is working.
Hopefully tomorrow early I can do a proper Proof Testing on the same settings again. The shot count on the barrel is up now (388 Shot Total) so I'll do a light wet swab of the bore before starting again.
I am encouraged with this tuner.

Today's conditions towards the end of the Testing...

[OS OK]

There is a man called heinz reinkemeier, I think he is German as I have a hard time trying to understand him...but...this guy is the KING of AIR RIFLES in my opinion. At least he is the most technical, most detailed and most sophisticated source I know of when it comes to competition and support of these air rifles. They are on a 'NEXT LEVEL' compared to anything I ever saw.
His YouTube site... https://www.youtube.com/watch?v=zu73kaRyezA

They are introducing a tuner...not just any tuner as we know them but a 'Star Wars Tuner' of sorts...take a look...





It has tuning adjustments with these screws, in and out to make the barrel emulate a different length and that brass part screws in and out as a fine tune adjustment also...



The part that got me excited is when this picture showed up in his introduction of this tuner!



Look at that...nowhere I have searched have I found anyone who suggests there is an 'X axis' in the harmonics of the barrel.
This is something that has been bugging me since the start.
I have theorized this by tracking the POI of the various 2-shot preliminary tuner groups & they have shown me an oval of sorts which suggests the 'X axis' but that has generated very little dialogue here.
This is the most exciting thing I could have hoped to discover thus far in my 'hairballed spitwads' about tuning.

Just wanted to share this before going out on the 50 today...see'Yas later boys.

[Harry Tobin]

that guy knows his stuff!!

[tazman]

That thing will be very expensive.
You realize you can buy a current model Harrell tuner just like the one you have on the CZ for $160 from the same place you buy your Eley ammunition?
They have to be bored to fit your rifle barrel but that is included when you order it.
No reason it wouldn't work on the Savage as well.

[Harry Tobin]

Hi tazman, what OK was saying is he is understanding what is going on with the barrel with this and he wasn’t going to buy it. It’s all all about understanding what going on, and old Ok is like a Bull Dog with a bone trying to understand barrel oscillations and what he can do to control it.

[tazman]

Hi tazman, what OK was saying is he is understanding what is going on with the barrel with this and he wasn’t going to buy it. It’s all all about understanding what going on, and old Ok is like a Bull Dog with a bone trying to understand barrel oscillations and what he can do to control it.

That is what I figured.
I just assumed barrels oscillated in whatever direction they wanted. I didn't think they were restricted to any one direction. I didn't mention it because it seemed obvious.
That equation series to figure out the harmonics that I mentioned in the other thread may apply here. That set of equations doesn't mention any direction because it takes all the directions into account by working with the length of the harmonic rather than the direction. Since the bore is round and the barrel is round, only the length of the harmonic is going to matter.
We all know what is going on with the barrel. Developing a method of stabilizing it or measuring it is the hard part. That requires testing equipment I simply don't have and cannot acquire.
Apparently, someone has done this testing and measuring and come up with some quantifiable results. It will be interesting to see how all this comes out in a form that can be made to work CONSISTENTLY across a lot of different equipment and ammunition. Lots of variables there.
It would be nice to have the ability to make some adjustments and have a consistently accurate rifle using a method that can accurately predict the needed adjustments rather than a random, try it and see method..