Hector's Airgun Blog

The 430L.- a Semi Custom powerplant, Part 1

7/12/2020

Back in January of '19, I posted the last entry about the 430L as an OEM rifle here

Sorry it has taken so long to get to this stage but, as usual, life has been busy.

Anyway, before we go into the subject matter we, again, yield the floor to our "Esquire", friend, and counsel, that says:

The conversion done here was carried out by a professional gunsmith. No warranties implied, or otherwise are intended in this article. The milling operations carried out here are sensitive, not devoid of dangers and of a high precision nature.
Do NOT attempt this conversion if you are not completely qualified to do so.
This conversion has NOT been sanctioned by Diana nor by Mayer & Grammelspacher.
This conversion proved safe IN THE GUN that it was performed. We cannot guarantee that all other guns will receive the conversion in the same way.
Please do not ask for measurements or dimensions, Connecticut Custom Airguns cannot provide these data.
All OEM designs and parts' shapes and dimensions are proprietary to Mayer & Grammelspacher and their Diana brand.

OK, so that's out the way, ;-)

In the previous entries to the 430L we discussed the HISTORY, the Potential, and what I THOUGHT would be the FUTURE

How wrong I was! ROFL!

But We did try. And I say WE because I enlisted the help of someone who really knows about ergonomics and human-machine interfaces.
But the challenge was a little too high without substantial modifications.

As time went by, the project fell into oblivion.

BUT, as it often happens to me, one EARLY morning (about 03:30 AM) my 3 year old daughter decided to play "musical beds" and landed in our bed.
I could not fall to sleep again, and I started thinking about the complicated changes that would be necessary to reduce the cocking effort and increase the shootability of the 430L.
As part of those "thought experiments" I referred back to my own re-design of the DIANA 54 action, a short stroke piston that yields overall efficiencies of around 49% (quotient between work input on cocking and pellet energy at muzzle) with the right pellets; through a change in the length of the stroke and in the fulcrum point of the cocking lever. An aspect that has been dealt with in Steve Herr's excellent "Saga of a 56 T/H":
Part 1,- https://www.ctcustomairguns.com/hectors-airgun-blog/the-saga-of-a-56-th
Part 2.- https://www.ctcustomairguns.com/hectors-airgun-blog/the-saga-of-a-56-th4603110
Part 3.- https://www.ctcustomairguns.com/hectors-airgun-blog/the-saga-of-a-56-th8042880 and
Part 4.- https://www.ctcustomairguns.com/hectors-airgun-blog/the-saga-of-a-56-th2541108

But, as an old Professor of Logic and Ethics once taught me: "If you want to truly master one theme argue Pro AND Against it. To learn what there is to learn".

And then is when it hit me in the face: We were going about this the WRONG WAY!

The change in Fulcrum point in the CCA WFTF D54 design was an opportunity afforded by the short stroke of the piston.

In the case of the 430L the action itself is already short stroked. The 430 is a short version of the 460. The 460 is a Magnum springer capable of delivering in excess of 21 ft-lbs in stock form. Of course everyone expects a "Magnum Springer" to have a commensurate cocking force, but no one wants that cocking force for a 12 ft-lbs yield.

Aligning the triggers between a 460 and a 430L we can see the differences

Squaring off the ends of the actions

As you can see there is quite a difference

The 430L improves on that huge cocking effort a little but at a Peak cocking force of 37.5 # it was still a bit much.
SOME gain can be obtained by using an HMO piston (ORing sealed), and that allows a shorter spring with less peak cocking force to be used, but still nothing really dramatic, and the gun still had the same feeling to it.

And then it became obvious that IF for a short stroke you need a long piston, for a short piston you could have a LONG stroke. A long(er) stroke would require also a longer cocking arc, and therefore, you can pack the same work into the action for less peak cocking effort.

This thought also meshed into a nascent design of a simplified piston made up of three parts, easy to machine and produce, it also has demonstrated superb resistance to a FEW dry fires and superior efficiency and uniformity, the strength lies in new materials that were not available 40 years ago.
For central transfer ports it has an added advantage at High Power output levels (24 ft-lbs), but we'll discuss that in another entry dedicated to a special 0.20" cal. D54.

Coming back to the 430L ¿what happens when you use a short piston?, AND more importantly: ¿How short is short?

And so, it was time to make the chips fly, make the idea a reality and test it.

These are the results.

In Stock/OEM form, the 430L has a cocking lever arc of about 103 °

More clearly seen here

Once the short piston is installed, then the cocking arc grows a little:

The new arc is 112° 45'

More clearly seen here

Now, from 103° to 112° 45' may not seem much, but it is nearly 9%
And, as such it is not surprising that the peak cocking effort goes down to 34#

One of the peculiar things about ergonomics is that a weight of 37# may feel "heavy", but a weight of 34# may feel "doable". Rationally, those 3# are "easy peasy", but when they are taken ON TOP of the 34# baseline, they become unbearable in a few dozen shots.
Under the current setup, you can cock the gun with the left hand while shooting with the right, or vice versa. Two handed cocking is not needed.

The other aspect is that the shot cycle is much improved. The mass of the piston just went down from 300 grams to 200 grams, and the cycle is just a sudden "thump".

On the left is the HMO/LS-430, on the right the OEM piston.

Originally, I had planned to do this with a specially designed spring, but time has precluded that and so, I will leave that for a "Part 2"; for the time being, the LS (Long Stroke) piston is powered by a Vortek PG-2/430 kit with an appropriately sized tophat.

Power-wise, the LS piston is no slouch; MV stats for 20 shot strings, AFTER 300 shots of "running in" with assorted pellets on the spring are:

JSB GTO's / 6.8.- 905 ± 6 fps for 12.4 ft-lbs
AA/JSB 8.44 / 4.53.- 796 ± 3 fps for 11.8 ft-lbs
BFT / 9.57.- 734 ± 3 fps for 11.5 ft-lbs
H&N FTT / 8,64 .- 772 ± 2 fps for 11.4 ft-lbs

But, as you can see, the lightness of the piston does favour light pellets.

Is this a drop-in mod? NOPE!

The stock requires some modifications and that makes us regard this modification under the same category as the conversion of the 34k Premium to NTec, or the conversion of the Mauser AM03 from NTec to steel spring with ABP.

For starters, the groove for the cocking linkage in the stock needs to grow, and then the cutout for the anti-beartrap safety also needs some lengthening.

Here are some pictures:

The stock viewed from above

A detailed look into the additional milling required.

At some point, I will re-finish these areas, for the time being, they will remain like this until I decide the train has truly arrived to the last destination.

For the tests, we equipped the gun with a Bushnell Nitro 6-24X50 FFP scope in ZR Mounts.

Yes, it is too large a scope for the little rifle, but testing does require a bit better glass than hunting.

And, how does it shoot?

Well, it seems that the 430L's characteristic "largeish" bore still prefers the Baracuda family, among them the BHE, and the BFT, but curiously enough, the gun also seems to like the FTT's

At 10 meters the accuracy is nothing short of exceptional: .

Moving out to 18 meters (20 yards) still shows excellent accuracy:

Tried to shoot at 40 yards (37 meters), but clearly, the current setup has reached, and passed, the limit:

I am sure that at 35 yards, with a better tuned MW (that will come in part 2), the gun is capable of "minute of Squirrel head" and so, would not hesitate to take this rifle out into the woods.
It is not a FT rifle (¿yet?!!!!) but it is perfectly usable in the East coast for squirrels and bunnies.
The black blobs in the above target are a little under ½" So, center to center, the BHE, the FTT 4.51, and perhaps the Baracuda Green, groups would all be in the 1" region.
Disappointing were the performances of the Crosman Premiers, but I truly expected that, given the bore of the gun.

Is there still some work to do?

Yup!
Hopefully, I will be able to launch the run of special springs for this most peculiar platform (the springs would also be a natural application to the DIANA 280, which is the breakbarrel version of the 430.
And once the final power source (spring) and guides have been finalized, we can then tune the Muzzlepiece in a useful manner.
So, I am reserving the opportunity to come up with a Part 2 to this blog entry. ;-)

Thanks for reading, keep well and shoot straight!

HM

6 Comments

One for the MSP's enthusiasts

6/18/2020

7 Comments

I still remember my GrandPa telling tales of how he would pump his airgun 7 times and then "aim straight at the eye" of doves to get dinner. I was 5 at the time, and in his stories, he was 10.

He was born in a large (as in thousands of acres and an island included) ranch in the Tamaulipas/Veracruz border before the Mexican Revolution. His father owned the ranch, and it was so far away from any road or rail, that it was easier to get to Europe by boat, than to go to Mexico City, or to the US border by land.
Boats came every month into Tampico (nearest seaport) and from there, it was only a 2 week trip by mule/oxcart to the ranch. Horses were for racing, or cattle wrangling, my GrandPa was a true "Charro".

Family lost the ranch to the Mexican Revolution, but his childhood was spent there and he went to the US, "sent" by his father to San Antonio, TX to escape the Revolution, where he bought an "Indian" motorcycle and studied Accounting. Though THAT is another story.

He prided himself to be crackshot with his airgun, and when the time came, he was the one that taught us the Marksmanship bases. He never had a firearm.

Of course, back then I didn't know what I know about airguns, their workings and their mysterious ways (which is why, for ME they are all female and that is another story all of its own), but he did provide a role model in many aspects:
- Make sure the FIRST shot is the last one.
- Make sure that IF YOU MISS, the pellet will not harm anyone/anything
- Take care of your things and your things will take care of you.
- DO NOT take more from Nature than you need.

Later in his life, he contracted Hodgkin's Disease which he survived for 10 years, in the end, he died when I was living in the UK (post-grad school) and I have always missed him.

Once I became an airgunner, I worked quite some time at improving the MSP's of the time. Living at 8,000 FASL the yield of spring-guns was "weak" to say the least, and the springs that worked for sea level provided a very harsh shot cycle. So an MSP pumped up 13 times (as opposed to the 10 needed at sea level, did provide useful energies and performance.
Sheridans were hard to work on, and then-current Benjamins were not that good.
I re-barreled a few 2100's into 0.20" cal when the best pellet in the world was the 14.3 grs. Premier in the cardboard box.
And the Lothar Walther barrels then in use also performed well with wadcutters:

Solid 0.20" cal. L-W barrel, RWS adjustable steel mounts, on a plastic stocked Crosman 2100 Shot like a dream. Even with the unblued barrel, LOL!

Crosman then came out with the 2200 series and then the 2275 (to celebrate the 75 years of Crosman, it came out with Walnut stocks and a medallion inset into the butt on the right side).
Setup one for FT and won several National Matches with it. Scope is a BSA 10-50X60 in BKL mounts. Do note that the sling is not attached to the gun (which was against the rules at the time) but attached to the upper forearm. Now, FT rules have gone vice-versa and it is against the rules to attach a strap to the body, but not to the gun . . . go figure.

I also made one in 0.25" to be used for "indoor pigeons".

And, when it was time for some serious hunting, I had to cover the plastic stock in suede to prevent the scratching noises from alerting the iguanas (whoever says Iguanas cannot hear, has not hunted them).

At a time, I had 4 VERY capable MSP's:

From the top: Custom Thumbhole Stocked Sheridan with peep sights. "Mr Franklin" the anniversary issue of the Benjamin 392 in walnut stock and grooved receiver. Custom built 1322 carbine (remember this was back in 2000). And custom 2500 with moderator.

1 of 500

When I left Mexico to come to the USA, I had to let go of them but, to this date, I kept the 0.25" cal "2500"

It is VERY special as it reminds me of my friends Mike Pearson and Jeff Wolgast.

Lots of good memories.

Fast forward a BUNCH of years and I find out that there is an MSP version of the DIANA Stormrider. It was called "The Seneca Dragonfly" and shared quite a number of parts with the Stormrider.

I started looking into it and the possibility arose to craft another 0.25" cal MSP that would be a proper "wood and metal" version of my beloved 2500. As happens with many of the gunsmith's personal projects, this had to wait, and wait, and wait . . .

It waited so long that the Dragonfly is no more under the Seneca brand, it seems it got displaced by the humongous "Aspen". This tells me that the people buying airguns nowadays have NO field experience.
"Urbanization" we'll call it, I guess, for lack of a better expression I can still print.

Soooooo . . . . all this to say that I have a very special connection to the MSP's and the persons that like them.

It shows that the shooter has a peculiar frame of mind. That he understands the rhythm of life and the balance of things. He understands the idea of using "just the right amount and not too much".

In short, a person close to my heart even if I haven't met him/her, yet.

And so, Mr. Mark G. enters the picture. Someone in Crosman told him to contact me to see if I could build ONE good gun out of two different variations of Crosman guns. He did, and we started corresponding.
The project interested me, even though I KNEW that the Artemis LR700-W that I had been saving for conversion to 0.25" was going to go. But Mark was so passionate about MSP's that it was impossible to not get energized and enthused with his ideas.

After some serious discussions, the argument came down to:
"Would you invest $200 in a Crosman 2100? I would not. But I would invest $200 in a Dragonfly."

And so he said, "OK, let's have a go at it"

The Crosman 2100 currently retails for about $70, the Dragonfly/LR700 retailed for $179. So, sinking money into a cheap thing will still be a cheap thing, but sinking money into a rough diamond, . . . that is different.

Having had the experience of all the previous MSP's I had definite ideas to implement:
- We were not going for power on the top end.
- We were going for power on the LOW end (1-4 pumps), and
- We were interested in reasonable accuracy with open sights BUT a fiber optic had to be used for the front sight.

And with all these ideas the conversion began:

- Gun was completely stripped off, cleaned and checked.

- Orings were replaced for good quality and material Orings.

- A part to replace the rubber "overpressure buffer" was turned from aluminum. This part was to allow the lubrication sponge to still do its job, and yet, NOT to compress at 6 pumps so that the effort required to overcome the friction of the expanded "plug" made the pumping effort unrealistic. The gun HAD to be useable at 8 pumps.

- A partial assembly was put together so that Mark could see exactly what he would be looking at once his gun was finalized:

Having approved this, we proceeded with the assembly.
- We used a Stormrider barrel that had been de-burred, fire-lapped, and the chamber had been trued. We used it because it already had the moderator.
It ended up like this:

Gun was re-lubed with Air Tool oil. Other oils are vaible, but the cost and availability of the Air Tool Oil makes more sense for the tune.

As you can see, the front "Fire Sight" (by Williams) is dovetailed to the front sight base of the Stormrider.
And it gathers quite the lot of light.
Initial testing was very encouraging, uniformity of MV's at all power levels was rewarding and accuracy at 10 meters was nothing short of impressive:

Initially, I had thought about tuning the gun for heavy pellets (Baracudas and Heavies of all brands), but Mark disabused me of my ignorance and told me to use light pellets. They shot straighter and were easier on the engine.
Well, after some tests, I have to concur.
Sighting in at distance threw back these:

The drop between 15 and 35 yards was simply untenable between the Baracuda FT (9.57 grs.) and the JSB RS's (7.33 grs.)
And again, testing at 35 yards proved that the RS's were the pellet to go to.

Once sighted in and settled down, the bottom 7 shot group, shot with 7 pumps shows that someone with more practice using open sights CAN shoot good groups.
A 1½" group at 35 yards with open sights is nothing to sneeze at. Still . . . practice is in order, LOL!

The other test that is important in MSP's is the overnight shot. You pump it up and let it sit overnight, then check the MV the next morning.
I have to say that this gun passed with good grades as the last average MV for a 50 shot string was 735 fps, while the first cold bore shot next morning was 721 fps. Not bad at all and perfectly understandable just from the cooling of the air chamber.

Test Setup.

From the technical standpoint:

One of the differences between the Artemis' version and the Seneca's is the slant cut at the division between the pump handle and the forearm. Different strokes and all that . . .

Some have argued that there a need to add a barrel band between the pump tube and the barrel. The targets dispel that theory. Further, the pump tube is severely stressed when pumping, you do NOT want to transmit that to the barrel.

In the present arrangement, there is a slight contact between barrel and end of pump tube, but that was not detrimental to the accuracy.

The front end of the Stormrider barrel is a true moderator, it is glued for legal reasons and it was left like that because one of the problems with ANY gun that dumps ALL the air, whether MSP or SSP, is that they are LOUD. This one, even with the small LDC is comfortably quiet.

As received, the gun yielded 12.7 ft-lbs with the Baracuda FT at 8 pumps. If we compare that to the other available MSP's we have that a UMAREX NXG will yield 5 ft-lbs, a Crosman Mk 177 will yield 5.7 ft-lbs. I do not know if the Mk 177 is still available, but it IS an interesting gun for youngsters. Personally, I do NOT like the "envelope" too military for my tastes, BUT I do understand the value of role play in the education of youngsters. Length of pull and weight are more geared towards the young crowd (as in 10 year olds), and the sights are/¿were? REALLY GOOD. But I repeat, I do not know if it is still on offer.

After the fitting of all the parts, this particular LR700-W yielded 13 ft-lbs on the dot but, more important than that was the performance at low power:
at 5 pumps it yielded 9.7 ft-lbs
at 7 pumps, it yielded 11.5 ft-lbs
This with the Baracuda FT.

But, once tuned to the RS's (7.33 grs.), even though the yield came in lower in energy, the accuracy was there, and that is what is important.
So , final stats were:
# of Pumps.- MV±sSD
1.- 388 ± 0
2.- 554 ± 4
4.- 700 ± 0
5.- 746 ± 2
6.- 783 ± 2
7.- 812 ± 3
8.- 840 ± 2

So, where to from here?

These results, and other experiments I have been conducting lately tell me that there is much to do in this architecture.
Would I use this mod as an SSP in a Match capability? Yes. With the right barrel and the right sights, there is no doubt in my mind that it could easily replace anything in the Avanti series.
At present, part of the conflict is in the "reach"; you need really long arms to get the whole pump cycle done without standing. For a youngster, that MAY be a problem.
A re-design is in order and there are a TON of things to improve.

Whether Air Venturi will decide to bring more into the USA is up to them. I may contact SPA separately.

One thing is for sure: EVERY airgunner should have one of these in his collection. Once modified, they are practically eternal airguns.

Keep well and shoot straight!

HM

7 Comments

Mandarins to Oranges

5/26/2020

4 Comments

INTRODUCTION

Most of you will know me as a "Science guy" and, yes, I guess I am more than a common NERD.

But life and experience have taught me that there is a lot of worthwhile knowledge to be gained from just listening to the users. Especially if the users are experienced and UNCOMMON persons, in the sense of having been endowed with more than a passing grade of "COMMON SENSE".

When I was much younger, my GrandMa used to tell me that the least common of senses was the common sense. After almost 64 years I have come to agree wholeheartedly with that.

Bill and I met by "accident" in one of the fora, we both love airguns, and German Airguns more precisely; and I cannot but see a future me (result of a strongly driven and purposeful youth with lots of physicality to it) in him.
One day my body will present the "bills" for all those strenuous activities.
And, while growing old is mandatory, it's growing up what I plan on keeping "optional" ;-)

To keep a capacity of wonderment, and the love of life, is what will make the next decade (or two), what it is supposed to be.

And so, in that spirit, I present you with a notable person, in the sense that he makes a lot of sense.

Oh!, and what does the title mean? Well it's sort of a private joke because while discussing the idea of this Blog entry, Bill asked me (and rightfully so), "Won't we be comparing apples to oranges here?"
My response was that there were sufficient characteristics shared by BOTH guns (HW30 and AM03) to think more about a comparison between Mandarins and Oranges: about the same, just slightly different size, zest and flavour.

¿Isn't that what life is all about?

;-)

I yield the floor to Bill:

Guest Blog by Bill Rickvalsky

Bill with the two guns he was charged of comparing: in his left hand, an HW30, in his right a modified DIANA Mauser AM03

Let me begin with a little background information. A few weeks ago I was involved in a discussion on a web forum about the possible acquisition of another air rifle. I had not too long ago acquired a Weihrauch HW30S as an addition to my Diana Model 34. The reason for that purchase was because the cocking effort of the Diana 34 had become rather fatiguing. The HW30S was a considerable relief in that regard. But then I began investigating the purchase of another rifle that might provide power similar to the Diana 34 but not be as difficult for me to cock.

The reason the cocking effort is an issue for me is that I am in my 70's and have a chronic health condition that occasionally affects my muscle strength. But I thoroughly enjoy my shooting and regularly have somewhat lengthy shooting sessions. The HW30S allowed me to do this without wearing myself out.

As a result of that forum discussion I was offered an opportunity by Hector to compare my HW30S to a Diana AM03 Mauser that had been modified with people in just my situation in mind, older folks with health issues. The AM03 started life as an NTec gas piston rifle. It now has a steel spring operating an anti bounce piston (ABP). The rifle is putting out 13 fpe and has a cocking force of 23 pounds. My objective was to report on the perceived cocking force and the shooting characteristics of this rifle and the HW30S.

From top to bottom: DIANA Mauser AM03; DIANA 34; HW30S

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.

Do any of you think this is poor shooting? Heck, No! It's good shooting in anybody's books.

As I was able to get in more shooting sessions I was paying particular attention to the shot cycle characteristics. The AM03 seems to shoot at an equivalent power level to my Diana 34 although my chronograph is not operational I had previously determined my Diana 34 put out about 13 fpe. But the shot cycle characteristics were very different. The AM03 has a sharper, crisper shot cycle than either the HW30S or my Diana 34. By that I do not mean the shot cycle is harsher. It just seems quicker and more stable. While the HW30S has a softer shot cycle it is only about a 6.5 fpe rifle. My impression after several shooting sessions was that the AM03 is less hold sensitive than my Diana 34 and is almost on the same level as the HW30S in that regard.

A couple of the shooting sessions I had were fairly lengthy with over 200 pellets down range. On those occasions the cocking effort of the AM03 and HW30S became an obvious advantage for me. I believe I could shoot either of those rifles all day long. I eventually would lay the Diana 34 aside while shooting the other two. I know there are people who do not find the Diana 34 difficult to cock. But it apparently crosses a threshold of work for me. I like the rifle and can shoot it for a while but there are limits.

One side comment I would like to make here is about the length of the cocking arm (barrel) and how it affects this. While many people say the longer barrel provides more leverage it also requires a longer reach, particularly when sitting. When reaching up to the end of the barrel my arm is fully extended and then has to swing out and down while still fully extended until more than half way through the cocking cycle. This actually is as much of a disadvantage as it is an advantage. I find it easier to not reach all the way to the end of the barrel.

Someone else's technique may give different results in this regard.

The AM03 seems a little louder from behind the gun than either of the other two rifles. It is not very much at all and may be related to the crisper shot cycle. But I am fortunate in being able to shoot without any concern for the noise levels of any of these rifles as none of them is really offensive in my rural neighborhood. And just as a check I asked my son to listen to them from about 20 yards away to the side. He felt that the Diana 34 and the AM03 were about the same. The HW30S as expected is quieter.

I would love to have a hybrid of the AM03 and the HW30S. I like the extra reach of the AM03 without paying a significant price in cocking effort. The AM03 that I am shooting is heavy, especially for occasional offhand shooting. But there are times I wish the HW30S had just a little more weight for offhand shooting. This light, short rifle sometimes seems a little twitchy without a rest of some sort. It would also be nice to have the barrel on the AM03 be two or three inches shorter. For me anyway the shorter overall length would balance better.

I would like to thank Hector for this opportunity to participate in this comparison and to possibly contribute slightly to upcoming design decisions. And I told him several times how much I love the set up on the trigger in this AM03. It is an absolute pleasure to shoot.

I hope everyone learns a little something from this old guy's comments. I know there are others like me out there who may have the same concerns.

Bill Rickvalsky

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

4 Comments

New "Super Custom" trigger for the Walther LGU/LGV

4/29/2020

4 Comments

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-lgu https://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:

As you can see, it uses a quite novel way of making it adjustable without making it expensive. At $80 retail, it is in line with what European triggers cost, and it does provide some advantages.

Among the advantages: there are two possible positions for a second stage, one that provides for a light pull, and another one that provides for an even lighter pull, at the expense of a little "crispness".
In a way this is similar to the Rowan Engineering version, but if we compare them side by side they are not quite the same:

From left to right: Walther's MA, Eric's trigger, and Rowan Engineering (RE) Trigger.
While the RE trigger allows the user to move the whole trigger blade back, it also ends up needing a "shoe" that is far too wide to operate/work on the trigger. If you want to remove the stock, or adjust the second stage (in the "heavy" position), you need to remove the blade and the holding post.
Eric's trigger does away with that.
Eric's blade is further back, and one of the common complaints about the LGU/LGV stock is that the pistol grip is really big and seems to be made for giant's hands.
Some shooters (even one previous World Champion) hold that huge pistol grips prevent the shooter from inadvertently twisting the gun when releasing the shot, and that is very true, but it is also true that techniques exist to teach ourselves to apply a slowly increasing force that does NOT twist the gun and therefore does not affect the shot. IN any case, the most common versions of the LGU that you see in the competition circuit have ALL had their stocks replaced.
As far as adjusting the distance between pistol grip and trigger blade, Eric's trigger uses a novel approach, and that is a pressure plate that can be moved in/out meaning that it shortens or lengthens that distance.
Eric's trigger is also a bit more swept back, and so the pressure plate could be used as a "Register Mark", ensuring uniform trigger finger placement.

When comparing the positions of the three screws we see that RE's trigger uses a fairly uniform spacing between screws, whereas Eric's trigger uses a skewed distribution that, while providing for an even "lighter" trigger pull, will definitely loose some "crispness" to the release.
We also note that RE's trigger has rounded screw faces, while Eric's trigger has pointed faces. This is a result of the market they are oriented at; RE's trigger is sold mostly to fairly amateur airgunners, as a "drop-in", while Eric's trigger assumes that users have ALREADY taken the time to stone and polish all interacting surfaces.

Yes, if you are looking for the LIGHTEST possible trigger pull in an "untreated" trigger block, then RE's trigger will give you that, BUT, if you are looking for a compromise between extreme lightness and total crispness and you are willing to stone and polish your trigger parts, or send them out to a Pro, then Eric's trigger can more easily accomplish this, and with less fuss because you can adjust all aspects of the trigger pull with the trigger blade in the gun, without the trigger guard (more on that later).

To install Eric's trigger is simple; you take apart the gun and when you have the trigger block out and the clamshell disassembled, you take out the old trigger (on the left is the OEM "economy" trigger with the lengthened screw of the "Yankee tune", on the right is Eric's trigger):

And put in the new one:

Eric recommends cutting one coil of the extension spring that is the return/no slack spring, but I did not find it necessary.
You will need a crochet hook or some other hook to get that spring out and then in again, so DO REFER the blog entry about "Swapping triggers" above mentioned.

Once you have swapped the triggers, you will need to adjust the screws.

Eric sends a very interesting manual that details STARTING points for the protrusion of those screws and I found the manual absolutely right. SO, DO READ IT!

Once that is done, you can close the gun and start the actual fine tuning.

It's important to note that once assembled, the gun should be checked that everything is in its place and the clamshell is properly closed and aligned.

Upon some extensive testing, I found that FOR ME, the flat pressure plate gave a "strange" feel, to the point of being distracting, because the pressure plate always keeps the same orientation, when lowered to the last hole, the feeling was that I was pulling in a "crooked" way.

While this would be ideal for shooters with custom stocks that almost always have a "vertical" pistol grip, it was somewhat off-putting to use with the sporter stock.

So, Eric agreed to make two versions: one with a curved blade, and another with the "flatish" trigger blade

I found also another solution that is truly viable only at very low trigger pulls, and that is replacing the screw with a button headed allen screw that presents a hemispherical shape to the touch of the hand:

The other thing I like is that I can use a locknut at the rear, to ensure that the setting does not get "out of place".
At trigger pulls above 1# this is somewhat tiring in the long run, but below that it is an eminently usable solution.

If you note, here I have a fully assembled and functional gun without the trigger guard, how is this possible?
Well, Eric designed and will include as part of the kit two plastic "D"s that allow you to get the gun back together to the point where you can actually shoot it, and still have completely open access to the screws for adjustment.
You can see one of the "D"s in the picture above.

I tested the trigger in an "untreated" LGU trigger block (my LGV being "on loan" for a lengthy and really serious experiment), mainly to see what difference the 40-60 minutes of stoning and polishing parts would gain a shooter, but also to get a feeling of how narrow the market would be for Eric (difference would be between a few hundred to a few thousand).
And I found out that the lightest trigger pull I could get was an extremely rewarding 1# 2 oz. with great consistency.
Almost anyone should be able to live with that.

In a stoned and polished trigger block, pulls can be lowered to levels that I would not consider safe for 90% of the shooters (just watch Eric's video referenced below), but in the end it is each and every one of us who are responsible for our actions.

Eric has also agreed to send, to those that request it, a "ball end" for the pressure plate, something like this:

Have not tried it, but it makes a lot of sense.

I was very happy to work with Eric on this project, and since he is still in the pre-production phase, there are some changes that will be inevitable.

BTW, you can see Eric's video here: https://www.youtube.com/watch?v=jvndvLfzug0&feature=youtu.be

If you are interested in finding out more about this trigger, or if you want to buy one, drop Eric a line at:
epianori@gmail.com

Let him know you saw this, please.

;-)

Keep well and shoot straight!

HM

4 Comments

The "HPM" or DIANA's High Performance Muzzleweight

4/25/2020

8 Comments

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:

A bit of history

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

First proposal and a "failure"

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:

The Future

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

8 Comments

<<Previous

Hector Medina

2012 US National WFTF Spring Piston Champion
2012 WFTF Spring Piston Grand Prix Winner
2013 World's WFTF Spring Piston 7th place
2014 Texas State WFTF Piston Champion
2014 World's WFTF Spring Piston 5th place.
2015 Maine State Champion WFTF Piston
2015 Massachusetts State Champion WFTF Piston
2015 New York State Champion WFTF Piston
2015 US National WFTF Piston 2nd Place
2016 Canadian WFTF Piston Champion
2016 Pyramyd Air Cup WFTF Piston 1st Place
2017 US Nationals Open Piston 3rd Place
2018 WFTC's Member of Team USA Champion Springers
2018 WFTC's 4th place Veteran Springer