The particular “HPM” or DIANA& #039; h High Performance Muzzleweight

I have received a few questions about this system (yes this is a SYSTEM), as well as a specific request from of my favourite persons in the airguns’ cyberworld, and the questions tell me that will without the IWA 2020 happening, plenty of what WE (DIANA) had hoped in order to relay to the users and achieve on the shooter’s information side basically DIDN’T  happen.

Questions furthermore tell me that people are not really updated about where the research and development of springtime guns is going. In a way, that is easy to understand, manufacturers are not doing the best of work in telling people how more complex today’s spring guns can be regarding those airguns that the Cardews’ examined in their legendary works.

So , let’s look at a little bit of background and how it percolated into the creation line of one of the foremost examples of used technology in the spring-piston airgun planet, then we’ll look into more recent tests, and how, finally, the product became a process to be included into the new release of the Air King (the AirKing Pro). Along the way, we’ll discuss exactly how sometimes even manufacturers fail to acknowledge the DIFFERENCES between an airgun and also a firearm.

So , why don’t get started:

A bit of history

Since my powder burning days (1966 to 2000), I have been a firm who trust in tuning the gun towards the projectile, and choosing the best projectile towards the task at hand. If you are familiar with the particular “Accuracy Node” concept, you know that rifles have a MV where the topic exists at the point where the barrel’s muzzle’s excursion is at its severe. Meaning that it is going in one path, stops, and then starts moving back again. Like a pendulum, but in a much more chaotic manner. So , following that strategy, the MV of airguns could be changed in small increments with the use of spacers in the spring, so that the pellet’s exit coincides with the end from the oscillation where the transversal velocity from the muzzle is as low as possible since it’s either stopping, at relax, or just starting to accelerate back.

Therefore , when I came across an industrial unit that offered to do that for your DIANA’s  I jumped into it. With time, I found the unit somewhat fragile plus capricious (getting out of adjustment on the worst possible time), till at some time, I had it glued (this  commercial Harmonics Tuning product has been discontinued about 15 years ago) , then in 2015, due to its dismal failure in a WFTC Suit , I decided to design something which would work in my favourite platform, the particular DIANA 54 AirKing.

Some time passed and I then arrived onto the realization of a fundamental characteristic of the DIANA 48-> 56 family: The barrel is in actuality a 15. 2 mm’s barrel or clip that has been encased in a shim then that shim goes INTO an eighteen mm’s  sleeve, that is what we observe. That is the nicely blued part that individuals take for a barrel, but it is not really.

In the past, SOME photographers used to fill the cavity between your shim, sleeve and barrel along with resin, or other compound, plus claimed to have improved the precision, but my problem with that method was that it was a FIXED solution. “Tuning” of your system would STILL have to play with the MV and seeking the “right” pellet.

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

I looked at all the current Harmonic tuning systems (firearms, archery, and airguns) and all but 1 depended on a weight that was rough and screwed or unscrewed together some position in the barrel, or perhaps a rod. The one that didn’t, depended upon moving the support position from the barrel in the stock (forend stress point bedding) therefore lengthening or even shortening the free-floated length of the barrel or clip, problem was that most spring-piston airgun barrels are free-floated by style.

So , I made a decision to combine both concepts and created a system that is comprised of a particularly dimensioned weight that can move backwards and forwards along its position on the barrel or clip with set spacers.
We worked through a few prototypes so when I had settled on something I actually published my results here in this blog entry.
At this point, do note that this happened within 2016, that’s 4 years ago!

Since then, most of CCA creates have benefited from this “gadget”, and from the knowledge and techniques this research brought. Further research has already been done and now we know not only how you can control, but how to REDUCE the harmonics at barrels’ muzzles (though which is another story; -) )

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

Therefore , when the time came to write the particular spec for a “new” 54, it had been normal for me to include this device in to the spec. In complete agreement along with DIANA, we decided to name it the particular HPM (for High Performance Muzzleweight).

The first appearance of the gadget to the public under the DIANA brand name was at 2020 SHOT Display, there is a whole thread about it here   where you will find links in order to videos, reviews and other comments; in addition to a lot of questions and answers.

And that brings us up to the existing

First proposal and a “failure”

It was towards the end of 2019 that I was told that regarding 300 “54 barreled actions” had been available and that we could use these to launch a re-vamped fifty four.
The problem was that there was SIMPLY NO BUDGET available for improvements. Meaning that no matter what we wanted to put in, had to originate from reductions and savings in the EXACT SAME model, that is a tough value-engineering issue: Improve a product AND make it price the same or less. Not easy with no technology leap. Still the challenge has been taken up by the team and we talked about a number of things that could be improved. Unfortunately, ALMOST ALL implied some cost raise. The exception was the Harmonics Tuner. A muzzle piece needs to be presently there, and the plastic one in present production, though not expensive, is not inexpensive either. It’s a complicated mould. Furthermore, the change COULD imply that the particular “Pro” model would be a scope-only gun, so the sights could also be eliminated. Finally, there was an extra operation on the barrel or clip to create the “key” where the front side fight ramp/muzzle piece needs to catalog to always keep the front sight upright. Between all these “savings” the Harmonics  Tuner seemed to be a good candidate.
It also promised to be the most affordability that would still be useful to ALL photographers (and here I want to remind a person that DIANA operates in more compared to 90 countries with 7 various power levels and some caliber/rifling/OAL lawful complications).

And, finally, changing it to the EMS system might be a breeze, so , after much believed, the concept of the Harmonics Tuner reached the forefront. The part is easy to make and easy to use, it does NOT emerge from adjustment, and use tends to attach it more and more firmly into the place.

Simultaneous to that particular I had started some serious utilize a friend with a scientific penchant that will tested the usefulness of the Harmonics Tuner in two completely different strength plants: A short stroked D56 as well as the “skinny piston” (22 mm’s data compresion chamber bore) version of the exact same gun. As different as pears and oranges.
You can read the outcomes of those experiments here:  

As you can see from the whole SAGA, the particular Harmonics Tuner proved its effectiveness in two completely dissimilar motors. It would be like testing a turbo-charger in a Mack Diesel Tractor Truck and a Subaru BRZ and still selecting improvements in both results.
As well as the HT was deemed an “easy to use” device, needing the discharge of the screws, the addition or even subtraction of an ORing and the disassemble of the gun, an operation that required less then 3 minutes for each test.

So , it had been DOUBLY annoying when DIANA’s mind gunsmith told me that they had not discovered any change in group dimension when tested in the factory, whatever the number of spacers added.   WHAT?
Fortunately, the Technical CEO told me they would still go ahead and planned the usage of the device, but that I had to create a new design, test and a procedure to show the usefulness.

Right after taking a day (or two) in order to calm down and analyze the whole thing, We decided to question the test procedure accompanied by the factory. It was then which i was told that the gun have been put on a vise that kept the sled system fixed, yet at an angle, that   modifications had been made from the original spec (aluminum instead of steel), and that only 2 screws, instead of the 6 that were initially specced had been used, granted that will perhaps my drawing had not been totally clear, but still the device built with the “Construction” section of the company was not the things i was talking about, these substantial modifications warranted a re-design and re-test, under  conditions that would be present in real life shooting.

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

A brand new material was sourced as Aluminium DOM bar, and new prototypes were made, but this time complying with the needed bodyweight (one of the most extended sets of experiments I actually conducted way back in 2015).
I then prepared a completely new check using one of the guns that were over the pipeline, and these were the results:

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

With these results in hand, I returned (electronically) to DIANA, and it had been agreed that the AirKing Pro stomach equipped with the device.

The unit itself is VERY simple and easy to make. Externally it looks just like an average Snout Weight, but the trick is inside, where ORings can be added or even removed to determine the position of the bodyweight along the muzzle. In the same way that utilizing a longer or shorter bar adjustments the “tone” of a grandfather time clock carrillon, the harmonics (vibrations) on the muzzle also change and this is exactly what determines the POSITION of the muzzle plus WHERE IT IS AIMING AT, when the pellet exits the muzzle.

Because ORings are added, the snout that was flush with the end from the HPM, becomes more and more “recessed” in to the cavity.
Using one of Steve’s excellent pictures, although that is a metal version of the HPM for the design 56, not the 54, you can view the make up of the whole program

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

The Future

Between four and 6 months after “re-start” from the world’s economy once CV-19 continues to be overcome, we should be able to see this particular in retailers and internet retailers.
There will be other options in share colors and, of course , a beech version.
The process to “tune” the rifle’s harmonics will be the exact same:  
1 . -Start through 0 ORings
2 . -Shoot three shots into a “waste” bullseye
3. -Shoot a five shot group at least 15 metres away (19 is preferrable).
4. – Add one ORing
5. – Repeat through 2
6. – Do it again from 4
When you achieve 10 ORings, STOP, you should view a “periodicity” each 4-> 6 Orings (depending on power level), decide on the two settings that are most encouraging and re-test till you are content 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 that, read this ), as the putting on in of the parts amongst on their own is an essential part of what airguns need to be able to deliver top precision, but if you want to “train” yourself within the procedure by all means do it several times. Simply understand that, in the end, you cannot put the buggy before the horses.

Wish this answers as many questions as normal before seeing/handling the actual matter.

Always open to queries or comments.

Maintain well  and shoot straight!

​ HM


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