​After receiving the AM03 and getting it set up to shoot everything went very smoothly and the rifle fit me well just as received. My quick impressions from the first shooting sessions were very favorable. The AM03 is heavy. The all up weight is 9 lbs. 11 oz. which is heavier than my Diana 34 at 9 lbs. exactly. My HW30S weighs in at 6 lbs. 12 oz. Both rifles are scoped. The cocking effort of the AM03 was perceptibly heavier than the HW30S but not by a significant amount. The difference between the two would not make me choose one over the other just based upon the work involved in cocking. My Diana 34 is significantly more work. The trigger on the AM03, which I understand is an Ntec T06, is very light and has a clean, crisp break. A very nice trigger so I can't blame my sometimes poor shooting on the trigger.

N.E. I would like to finish this entry by thanking Bill for his time and effort.

And yes,I learned things that we expect to put in place with the new EMS line at DIANA.

The 34 EMS will allow users to "tailor" the gun in such a way as to suit THEM.

Particularly in Bill's case, I am already envisioning a 34 EMS with the NTec trigger, a lightweight ABP unit inside the OEM piston, a shorter barrel, and a Carbon Fiber moderator/Harmonics Tuner in place. The short barrel will save 1 full pound of weight, the Carbon Fiber mod/HT will save another ¼ lb, and a beech stock will also save another ¼ lb, so, all in all, with a Traditions lightweight scope in small ZR Mounts, we could be looking at a 7 to 7¼ lbs all up rifle still capable of delivering 12 ft-lbs at the muzzle with a bit over 25# peak cocking force.

Now, THAT would be an interesting little gun, LOL!


Keep well and shoot straight!





​HM

BEFORE ANYTHING ELSE, I am required to post this, the legal disclaimers:

1.- Swapping the trigger blades WILL invalidate the warranty of your rifle.
2.- ANY user intervention in the triggers MAY result in an UNSAFE condition. Once you get into the trigger you are on your own.
3.- I have no control of YOUR actions, so I can take NO responsibility for the results YOU get. This process proved safe and sound in MY gun. I cannot guarantee that it will be the same in YOURS.

Back in May 2018, I wrote a note about the then available "Super Custom" Triggers for the LGU/LGV rifles.
In the original post we discussed European versions, but on this one we will discuss an American design.

For those that have not followed my interest in these fine guns, I would suggest you take the time to read these entries:
https://www.ctcustomairguns.com/hectors-airgun-blog/the-walther-sport-family 
https://www.ctcustomairguns.com/hectors-airgun-blog/swapping-the-walther-lgus-trigger 
https://www.ctcustomairguns.com/hectors-airgun-blog/a-yankee-tune-for-the-walther-lguhttps://www.ctcustomairguns.com/hectors-airgun-blog/a-yankee-tune-for-the-walther-lgu-second-version 
https://www.ctcustomairguns.com/hectors-airgun-blog/the-walther-lgv-a-second-look 
https://www.ctcustomairguns.com/hectors-airgun-blog/the-walther-lgv-pushing-the-power-limits 
https://www.ctcustomairguns.com/hectors-airgun-blog/the-supercustom-triggers-for-the-walther-lgu-and-lgv

As you can see, I am a great fan of the LGV, considering it the best breakbarrel rifle in recent production. We would have to go a few decades into the past to get something better.
These models had been in production for less than 6 years, and in those 6 years, not less than 4 trigger blades came into the market, WHY?
Savvy airgunners have been puzzled about how could Walther put such a bad trigger on such a good gun.

And here is where I sometimes ask myself questions that I know would be very "uncomfortable" for a manufacturer to answer, but that definitely point to a marketing strategy that fails to take into account the simple truth that "There are no second 'First Impressions' "

If we analyze the cold facts, they are:
- Rifles are very good rifles, among the breakbarrels, the LGV has no peer. The LGU faces stiff competition from other fixed barrel rifles that are just as good, if not a bit better, depending on the criteria used for judging.
- Price, when they hit the market was high. Granted, ALL airgun prices were high back then; in general, prices have come down as demand has grown, production volumes have gone up, and more brands/models are available.
- Simultaneous to the launch of the rifle itself, Walther launched a "Match Abzug" (MA) that promised a better release but, again, price was high.
- In at least one market, the rifles were ONLY available WITH the MA, at considerably higher price still.
- At some point, up to 6 different "variants" were offered of the LGV. From "De Luxe" models to "Workhorse" models.

To be honest, as a marketing strategy, this is a recipe for trouble.
Those that could ONLY buy the expensive versions thought about it and probably didn't, or if they did would always question their decision.
Those that bought the "economy" versions would not buy the accessory trigger.

Everyone agreed that the guns were between good and great, but still the market response did not justify the costs of production, one by one, the different variants of the LGV were dropped. Unconfirmed information says that Walther has decided to discontinue ALL breakbarrel rifles. Even when the attempt was never made to market the "Century" (a sort of economy LGV with all the good characteristics, but none of the fineries) in the USA
Which is a pity.

And it is what brings us to this entry.

As with many things in this "CoVid-19" world of "stay at home and do something", some people with the skills and the machines in their workshop now have the time to actually do some serious stuff.
In my cybertravels through the airgunning community, I came across an interesting post about "yet another offering for triggers" for the LGU/LGV, and it piqued my curiosity.

And this is how I met Eric. Eric lives in Texas, and he is a great guy. Modest and unassuming, it's a pleasure to deal with him. He is also talented. At first he said he had developed another trigger for the LGV/LGU rifles but that he needed to polish some aspects, a few months later, he comes up with fully finished prototypes. So many corporations would LOVE to have that time of "Start to Finish R&D", LOL!
SOooooo...
Let's get to the trigger:

I have received some questions about this system (yes it is a SYSTEM), as well as a specific request from one of my favourite persons in the airguns' cyberworld, and the questions tell me that without the IWA 2020 happening, a LOT of what WE (DIANA) had hoped to relay to the users and accomplish on the shooter's information side simply DIDN'T  happen.

Questions also tell me that people are not really up to date about where the research and development of spring guns is going. In a way, that is understandable, manufacturers are not doing the best of jobs in telling people how more advanced today's spring guns can be in relation to those airguns that the Cardews' analyzed in their legendary works.

So, let's look at a little bit of history and how it percolated into the production line of one of the foremost examples of applied technology in the spring-piston airgun world, then we'll look into more recent experiments, and how, finally, the product became a system to be included into the new edition of the Air King (the AirKing Pro). Along the way, we'll discuss how sometimes even manufacturers fail to recognize the DIFFERENCES between an airgun and a firearm.

So, let's get started:

Ever since my powder burning days (1966 to 2000), I have been a firm believer in tuning the gun to the projectile, and choosing the best projectile to the task at hand. If you are familiar with the "Accuracy Node" concept, you know that all rifles have a MV where the bullet exists at the point where the barrel's muzzle's excursion is at its extreme. Meaning that it is going in one direction, stops, and then starts moving back. Like a pendulum, but in a much more violent manner. So, following that methodology, the MV of airguns can be changed in small increments through the use of spacers in the spring, so that the pellet's exit coincides with the end of the oscillation where the transversal velocity of the muzzle is as low as possible because it's either stopping, at rest, or just starting to accelerate back.

Therefore, when I came across a commercial unit that offered to do that for the DIANA's  I jumped into it. Over time, I found the unit somewhat fragile and capricious (getting out of adjustment at the worst possible time), till at some point, I had it glued (this commercial Harmonics Tuning product was discontinued about 15 years ago), then in 2015, as a result of its dismal failure in a WFTC Match, I decided to design something that would work in my favourite platform, the DIANA 54 AirKing.

Some time passed and I then came onto the realization of a basic characteristic of the DIANA 48->56 family: The barrel is in reality a 15.2 mm's barrel that has been encased in a shim and then that shim goes INTO an 18 mm's  sleeve, that is what we see. That is the nicely blued part that we take for a barrel, but it is not.

In the past, SOME shooters used to fill the cavity between the shim, sleeve and barrel with resin, or other compound, and claimed to have improved the accuracy, but my problem with that approach was that it was a FIXED solution. "Tuning" of your system would STILL need to play with the MV and finding the "right" pellet.

I wanted a simpler device, something that would allow you to re-tune the gun should you change pellet batches, or wanted to change brand, power level, or any other thing. Something that would allow you to set a velocity (according to some rules, or other criterion set by YOU), and then tune the gun to THAT. In other words, command the gun and not be commanded by it.

I looked at all the existing Harmonic tuning systems (firearms, archery, and airguns) and all but one depended on a weight that was knurled and screwed or unscrewed along some position in the barrel, or a rod. The one that didn't, depended on moving the support position of the barrel in the stock (forend pressure point bedding) therefore lengthening or shortening the free-floated length of the barrel, problem was that most spring-piston airgun barrels are free-floated by design.

So, I decided to combine both concepts and came up with a system that is comprised of a specifically dimensioned weight that can move back and forth along its position on the barrel with set spacers.
I worked through a few prototypes and when I had settled on something I published my results here in this blog entry.
Now, do note that this happened in 2016, that's 4 years ago!

Since then, most of CCA builds have benefited from this "gadget", and/or from the knowledge and techniques that this research brought. Further research has been done and now we know not only how to control, but how to REDUCE the harmonics at barrels' muzzles (though that is another story ;-) )

Almost three years ago, I started working closely with DIANA, and since there were talks to bring this technology (and others) to the public/shooters of DIANA airguns, I did not pursue further the commercialization of the product.

So, when the time came to write the spec for a "new" 54, it was normal for me to include this device into the spec. In complete agreement with DIANA, we decided to name it the HPM (for High Performance Muzzleweight).

The first appearance of the device to the public under the DIANA brand was at 2020 SHOT Show, there is a whole thread about it here where you will find links to videos, reviews and other comments; as well as a lot of questions and answers.

And that brings us up to the present

It was towards the end of 2019 that I was told that about 300 "54 barreled actions" were available and that we could use those to launch a re-vamped 54.
The problem was that there was NO BUDGET available for improvements. Meaning that whatever we wanted to put in, had to come from reductions and savings in the SAME model, that is a tough value-engineering problem: Improve a product AND make it cost the same or less. Not easy without a technology leap. Still the challenge was taken up by the team and we discussed a number of things that could be improved. Sadly, ALMOST ALL implied some cost increase. The exception was the Harmonics Tuner. A muzzle piece needs to be there, and the plastic one in current production, though not expensive, is not cheap either. It's a complicated mould. Also, the change COULD imply that the "Pro" model would be a scope-only rifle, so the sights could also be eliminated. Lastly, there was an extra operation on the barrel to create the "key" where the front fight ramp/muzzle piece needs to index to always keep the front sight straight up. Between all these "savings" the Harmonics  Tuner seemed to be a good candidate.
It also promised to be the most value for money that would still be useful to ALL shooters (and here I want to remind you that DIANA operates in more than 90 countries with 7 different power levels and some caliber/rifling/OAL legal complications).

And, finally, adapting it to the EMS system would be a breeze, so, after much thought, the concept of the Harmonics Tuner came to the forefront. The part is simple to make and easy to use, it does NOT come out of adjustment, and use tends to affix it more and more firmly into its place.

Simultaneous to that I had started some serious work with a friend with a scientific penchant that tested the usefulness of the Harmonics Tuner in two completely different power plants: A short stroked D56 and the "skinny piston" (22 mm's compression chamber bore) version of the same gun. As different as apples and oranges.
You can read the results of those experiments here:

https://www.ctcustomairguns.com/hectors-airgun-blog/the-saga-of-a-56-th 
https://www.ctcustomairguns.com/hectors-airgun-blog/the-saga-of-a-56-th4603110 
https://www.ctcustomairguns.com/hectors-airgun-blog/the-saga-of-a-56-th8042880 
https://www.ctcustomairguns.com/hectors-airgun-blog/the-saga-of-a-56-th2541108 

As you can see from the whole SAGA, the Harmonics Tuner proved its usefulness in two completely dissimilar engines. It would be like testing a turbo-charger in a Mack Diesel Tractor Trailer and a Subaru BRZ and still finding improvements in both results.
And the HT was deemed an "easy to use" device, needing the release of the screws, the addition or subtraction of an ORing and the reassembly of the gun, an operation that took less then 3 minutes per test.

So, it was DOUBLY annoying when DIANA's head gunsmith told me that they had not found any change in group size when tested in the factory, regardless of the number of spacers added.  WHAT?
Luckily, the Technical CEO told me that they would still go ahead and planned the use of the device, but that I had to come up with a new design, test and a procedure to demonstrate the usefulness.

After taking a day (or two) to calm down and analyze the whole thing, I decided to question the test procedure followed by the factory. It was then that I was told that the gun had been put on a vise that held the sled system fixed, but at an angle, that changes had been made from the original spec (aluminum instead of steel), and that only two screws, instead of the 6 that were originally specced had been used, granted that perhaps my drawing had not been completely clear, but still the device built by the "Construction" section of the company was not what I was talking about, these substantial changes warranted a re-design and re-test, under conditions that would be found in real life shooting.

And here is where there is a lesson: If you need to test something that is going to be used under field conditions, then test it under the same field conditions.

A new material was sourced as Aluminum DOM bar, and new prototypes were made, but this time complying with the needed weight (one of the most lengthy sets of experiments I ever conducted way back in 2015).
I then prepared a completely new test using one of the guns that were on the pipeline, and these were the results:

As you can see, adding or deleting ORings yielded observable and measureable results. Dispersions went from horizontal to vertical and then back, and too many ORings (same as too large a weight) produced horrible results.

With these results in hand, I went back (electronically) to DIANA, and it was agreed that the AirKing Pro would come equipped with the device.

The device itself is VERY simple and easy to make. From the outside it looks just like an average Muzzle Weight, but the trick is on the inside, where ORings can be added or removed to determine the position of the weight along the muzzle. In the same way that using a longer or shorter bar changes the "tone" of a grandfather clock carrillon, the harmonics (vibrations) at the muzzle also change and this is what determines the POSITION of the muzzle and WHERE IT IS AIMING AT, when the pellet exits the muzzle.

As ORings are added, the muzzle that was flush with the end of the HPM, becomes more and more "recessed" into the cavity.
Using one of Steve's excellent pictures, although that is a steel version of the HPM for the model 56, not the 54, you can see the make up of the whole system

The other difference you will find is that while 3 screws are enough for 12 ft-lbs, for 24 ft-lbs you need 6.
But the principle is the same: You add or delete ORings to bring down the group size with the pellet you want to use (within reason).
As it was demonstrated and re-tested, in a normal 54, the results were verifiable and repeatable:

Between 4 and 6 months after "re-start" of the world's economy once CV-19 has been overcome, we should be able to see this in retailers and internet sellers.
There will be other options in stock colors and, of course, a beech version.
The process to "tune" the rifle's harmonics will be the same: 
1.-Start from 0 ORings
2.-Shoot three shots into a "waste" bullseye
3.-Shoot a 5 shot group at least 15 meters away (19 is preferrable).
4.- Add one ORing
5.- Repeat from 2
6.- Repeat from 4
When you reach 10 ORings, STOP, you should see a "periodicity" each 4->6 Orings (depending on power level), settle on the two settings that are most promising and re-test till you are happy that you are at the best possible point.

I would advise to "Run in" the rifle BEFORE the tuning (if in doubt about what is the BEST way to do this, read this), as the wearing in of the parts amongst themselves is an essential part of what airguns need to be able to deliver top accuracy, but if you want to "train" yourself in the procedure by all means do it several times. Just understand that, in the end, you cannot put the carriage before the horses.

Hope this answers as many questions as is normal before seeing/handling the actual thing.

Always open to questions or comments.

Keep well  and shoot straight!





​HM

DISCLAIMER;

First of all, an apology. Steve and I started exchanging more and more information and I got carried away on a tangent. He was kind enough to "call me back on track". Perhaps I am too much of a scientist and love bare truth too much. So, I need to rely on good friends to make me see the forest, as I am too entangled in the trees; the delay is mine and mine alone.

What follows are my own personal observations, conclusions, and hopes of further work.
I take full responsibility for what I say or write. If someone demonstrates me that I am wrong, as I have done in the past, I will stand corrected.
Nobody's "Purfect".

Let's re-cap: the FOCUS of this series of articles was the Harmonics Tuner (HT); a relatively simple device that allows the shooter to tune a gun to the best possible performance of a given pellet in the gun, WITHOUT altering the MV.
​
The idea was to compare the performance of the HT under two completely different powerplants to see if there was ANY measureable improvement from both, as different as they are.
As you can see from the results, there is. Smaller or larger, but there is a measureable improvement.
This is what I feel is most original.
Typical airgun tuning is done through cutting coils, change of springs/guides, change of pellets, and adding or removing washers that go from full sized spacers to paper thin power adjusters. BUT that means altering the trajectory (because MV changes) so that accuracy can be obtained.
The HT, in a way and within reasonable limits, allows us to "have our cake and eat it too"; because we can select an MV (obviously within the stability range of the pellet we want to use, and assuming that the barrel does not deeply dislike the pellet), and THEN tune to optimal accuracy and precision (depending on what we want to do with the airgun) to the best possible results within that system.

I have also received "questions" about the validity of using 5 shot groups as "data points" being that sometimes variations between groups are as large without any change, as they are when performing small changes. As limited as our tests were, we are confident that the results are reproducible in any individual's airgun, as long as the proper procedures are followed. 
​The RESULTS for individual guns may be different (as is normal with most aspects in airgunning), but everyone can find an "optimum spot" for harmonics tuning.
​That is part of the essence of the beast.

So, having clarified all that, let's get going

We might make some tweaks still, as this is a pre-production model.
​We are working on making the HPM available as an after market part for ALL 54's (as usual, in good DIANA tradition, it will be fully compatible with all previous editions of the 54, though the T01's may need a little gunsmithing).
I am told that the stock will be available in several colors and that also more traditional Beech (and perhaps some Walnut) stocks will be made available. It all depends on the wholesalers, so if you are interested, write to your favourite wholesaler to request some attention to the point of your interest.

Steve and I have been exchanging a lot of interesting information, and I have also been receiving results from the Harmonics Expert, such as this:

So, I will be writing another entry, this one dedicated to a more detailed and better analysis of what TRULY happens with the spring-piston shot cycle, what determines the efficiency, what are common misconceptions about it, and analyzing more in depth the "phases" of the shot cycle.

Just to give you an advance taste:
The curve above belongs to an ASP 20
You can clearly see that the first acceleration spike (red oval) is where the piston reaches the end of the air compression run, and that a few msecs later (green oval) there is an even greater "slam" BUT, the human senses cannot detect it.
You can also see the 70 g's force vibrations developing during the time of the pellet in the barrel (-20 to +50 g's for 7 msecs, though the dwell time of the pellet in the barrel is shorter).

It takes relatively sophisticated instruments to detect and measure them, not only in magnitude, but also in time. The chart also shows a good, long decaying vibration pattern (blue square).
And all this from a gas spring gun that has been reported as a "smooth shooter" and excellent at bench rest.
¡Surprise!

Anyway, it will be fun to actually make the real behaviour of the shot cycle evident for different airguns. And to see what works and what does not work, independent of what shooters "feel".

Conclusions:

The HT is a device that has been tested and proven in different power plant designs and has proven its value.

​DIANA will include it in the next " edition" of D54 rifles.

There are still other technologies that await research; as long as there are people that are fascinated by the spring-piston airgun, whether it is a steel spring, or a gas ram, there will be things to discover and improve.
And THAT is also part of the magic of airgunning.

Again, I need to thank Steve for his excellent participation and impeccable work. It has been a great pleasure working with him on this.
And also thanks to our readers because without dedicated airgunners willing to read a LONG, FOUR part, entry our words would be like the sound of a tree that falls in the middle of an empty forest . . .

Keep well and shoot straight!






​HM

N.E.
For those of us that remember B&W TV, "B" Westerns, and were raised on a visual diet of clear-cut good and evil as white hats and black hats, the name 'Dragnet' will always recall Det. Sgt. Joe Friday.
And badge # 714 will always mean dedication to the truth and unswerving loyalty to the Law.
Among its most famous phrases:
"All we want are the facts, Ma'am"
In honor of such a simple, unswerving, and devoted to service attitude, we decided to title this entry.
​
Take it away, Steve!
​

​As promised, I wanted to provide you with more in depth detail and comparisons between the two power plants that were used in the recent Harmonic Tuner testing.  

I mentioned in that write-up that after recrowning the barrel on my 56TH, Hector completely assembled my barreled action with some of his own components and returned to me for  testing.  It arrived with one of Hector's Short Stroked HMO powerplants, a tuned T06 trigger and the most beautifully detailed Diana 54 stocks I have ever seen! He went all out on this set up provided to me for testing.

We have already seen the rifle in action during the Harmonic Tuner testing.  Now lets turn our attention to the powerplants,  beginning with the Short Stroke HMO set-up.

28mm x 76mm HMO Short Stroke

The set-up as provided to me included everything you see pictured below;

Compression Tube with Reinforced Breech Seal
HMO piston
Main Spring with dual guides
Cocking Handle with modified fulcrum and linkage extension

It was set up for my requested energy level (11.2 to 11.4 fpe range)

​The HMO piston is a work of art with an o-ring main seal, nylon top cap, and a rear guide that is nicely machined to ride solidly inside the action, an improvement to the flared out piston skirt on factory pistons. 

You can also see the dual spring guide set-up.  This includes a conventional guide that inserts into the main spring, and an outer guide that surrounds the spring.

​Looking at the Transfer Port you can see the seal has a center reinforcement collar measuring approximately 3mm ID.

​The piston weighs in at about 317 grams.

​Inside the outer spring guide are the preload spacers, one of which appears to be a softer compound anti-bounce washer.  It is the blue washer in the picture below.

​I mentioned the "Modified Fulcrum" on the cocking handle.  Here is a close-up showing the re-positioned cocking linkage pin.

​The linkage rod end is solidly supported with nylon washers on either side for a smooth cocking stroke.

​To account for the relocated pivot point, the linkage rod has a threaded extension added.  In this picture you can see a factory linkage rod (bottom), alongside of the modified cocking linkage (top)

​It is evident that Hector has done his homework on this set-up.  It is precise, consistent and was easily tuned on target using the harmonic Tuner.  The cocking stroke is extremely light and will have you questioning whether or not your are truly making over 11fpe.

After all testing was complete, I purchased this set-up from Hector.  It is well made, durable and easy to tune on target.  I was able to successfully tune to sub 3/16" c-t-c 5-shot groups across two series of tests at 32 yards.
​
AGT 22mm x 96MM Skirtless

This set-up has been covered in much greater detail in a couple posts I have made on GTA and AGN, but I will give a quick overview;

This set-up consists of a factory Compression Tube sleeved down to 22mm.  The transfer port retains the factory 4.1mm ID.

The piston uses the factory piston rod, and has a dual seal piston affixed on the end.  The dual seals consist of a parachute seal and an o-ring main seal, and help reduce the effects of temperature changes on your velocities.  The piston also has two supporting guide bearings, with a special top hat that also functions as a third support bearing.

This is an exceptionally smooth powerplant and was producing groups as small as 1/4" c-t-c at 49 yards.  It is also very well made, solid and durable.  Adjusting preload can be done without a compressor.  I am able to compress the trigger assembly into place with one hand and insert the trigger block pins with the other hand.

​This piston weighs in at 149.5 grams

​In addition to the mechanical and dimensional comparisons, I also set up a test to measure the cocking effort for each set-up.  

This was accomplished by taping a Protractor above the Cocking Handle, centered directly over the pivot point.  The rubber grip cap was removed from the cocking handle and a slotted wooden block was inserted inside the end of the handle.  The block was supported by rubber sheeting, and had a groove in the center.  I then looped a wire tie around the handle, centered in the groove.  The rifle was supported firmly in a padded support and measurements were taken using a digital scale. 

The weight measurements were taken at specific locations in the cocking stroke, with the max reading being recorded just before the piston rod contacted the trigger mechanism.  Due to the differences in cocking stroke length across the power plants, the max readings were not the same as you can see in the chart below.

The pull point was centered right where you would place your hand when cocking the rifle and scale was kept inline with the direction of pull.

Here is the set-up for testing: