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Accessories Beeman R9 with Vortek center-latching air piston: Part 1

Beeman R9 with Vortek center-latching air piston: Part 1

by Tom Gaylord
Writing as B.B. Pelletier

This report covers:

  • The Vortek unit
  • Filling the unit
  • How it works
  • Spring guide
  • Installation
  • Disassembly
  • Piston
  • Barrel goes back
  • End cap in
  • Compressor
  • How long and how difficult?
  • Summary

I try to stay away from products that are not available, but today I’m starting a look at a new gas piston unit for the Beeman R9/Weihrauch HW95 breakbarrel rifle. This report will be unique in several ways. First, it is the first look at a new Vortek gas spring unit that may either be available from Pyramyd AIR or from Vortek directly. Second — the R9 I’m using for this test is in .20 caliber. I know there are many shooters who favor .20 caliber, but many more who don’t. I will address that as the report unfolds, but let me state for the record that, except for testing a Sheridan Blue Streak or Supergrade, I haven’t tested another .20 caliber air rifle in many years!

The Vortek unit

This new gas piston is so new it doesn’t even have a name as I’m writing this. I will call it the center-latching unit, or CLU for short. It came to me as a kit that included the unit, a piston seal, a white spring guide and an adaptor. But, an adaptor for what?

Vortek CLU kit
The CLU kit came with the unit, piston seal, spring guide and fill adaptor.

The adaptor is one of the things that makes the CLU special. It’s a fill adaptor that has a male Foster filling to attach to a source of high pressure air — preferably a hand pump. You see, this unit is filled by the owner!

Theoben used to allow users to pressurize their gas springs many years ago. I’ve owned several Theoben rifles with this feature. The problem was, too many owners were over-pressurizing their gas springs in attempts to get the last f.p.s. of velocity, and they were ruining their airguns. Ben Taylor — the Ben of Theoben — once told me that owners would pressurize their gas spring too high, turning them into slide hammers that beat their rifles apart. Davis Schwesinger told me the same thing, and I have shown you the results of such abuse.

burned piston seal
This piston seal was taken from a Theoben rifle that had been shot while over-pressurized. The rifle was losing power as the piston seal vaporized.

The Vortek unit doesn’t fix stupid. You still have to use sense when you manage your own gas piston pressure, and this report will look at how that’s done. And, if you are going to tune the unit, you have to have a chronograph. Sorry, guys, but the “back door to the hickory tree” chronograph won’t work for this. You can still fill the unit with a hand pump and it will work, but a chronograph is needed to refine it. I will tell you the pressure I filled to in a moment.

Filling the unit

Vortek sent me the unit with a low pressure inside to keep the inlet valve closed. I was to pressurize it myself. I was told it would take just 8 ot 9 pump strokes, but that will only work if I have the exact hand pump they use. Not just the same model — the same pump. Because things like the length of the fill hose will play into this. And it did. They have a 6-inch microbore hose. Mine is 24 inches liong. The hose is going to take more air to fill.

So, fill the unit until it has at least 45 bar of air pressure inside. That’s 653 psi. But you can go up to 700 psi and still be okay. I filled the test unit to 675 psi for the first test. The muzzle velocity will tell me what to do after that.

Vortek CLU fill port
The fill adaptor on the right is screwed into the top pf the piston, left. The ridge in the center of the flats of the piston are where the cocking shoe rides.

How it works

When I first examined the unit I found it impossible to compress the rear latch of the piston. It didn’t move! Vortek had told me there was just a maintenance charge of air in the unit, and I thought I should be able to compress it easily. So I called Vortek.

Spring guide

Tom Gore told me I could put all my weight on the latch — it still wouldn’t move. Because it never moves. He had me put the white plastic spring guide on the tail of the piston and then press down. That worked! Okay, this unit works differently that any one I’ve ever seen.

Vortek CLU spring guide
Here we see the end of the piston that engages the end of the white plastic spring guide. The hollow end of the guide fits into that groove on the back of the piston and shoves it forward. This is an entirely new way for a gas piston to work, and it is patented.

Vortek CLU flats
The ridge in the center of the flats of the piston is where the cocking shoe rides.


Pyramyd AIR sent me the R9 rifle they display at trade shows. It had no mainspring, because no gun inside those shows can be operational. So, disassembly should be pretty easy. But I haven’t taken an R9 apart in a long time, so let’s see how it goes.


First the rifle comes out of the stock. The rest of the installation is done on the barreled action. Now remove the Rekord trigger.

Vortek CLU Beeman R9 trigger
Drift out the trigger pins and remove the Rekord trigger.

The mainspring is out of this gun, but if it was in the gun a compressor would have to be on the end cap before the next step.

The R9 doesn’t have a threaded end cap like the Beeman R1 and other Weihrauch airguns. Instead, the end cap is held in by one locking flange and four tabs. A new R9 can be somewhat tedious to take apart because those tabs that have to come out first are very tight in their holes.

Vortek CLU Beeman R9 tabs
Those two tabs and two on the other side of the spring tube have to come out. In took this picture before the trigger was removed.

Vortek CLU Beeman R9 tab hole
Remove the tabs from inside the end-cap. Anything short and angled works — like a small Allen wrench.

Vortek CLU Beeman R9 tab out
When one tab is out you can insert a pin punch through its hole to pop out the other tab.

Vortek CLU Beeman R9 cage rotated
With all tabs out, the end cap is rotated to free the locking flange (arrow).

If there was a mainspring in the gun the end cap would be under tension at this point and a mainspring compressor would have to be used. This one had no spring, so the cap slid out easily.

Vortek CLU Beeman R9 cap out
The end cap is removed.


Because there was no mainspring in the gun, things have been easy to this point. But there is still a piston inside, and it needs to come out for the CLU to be installed. To get it out, the barrel has to be removed. That’s because the cocking linkage cannot be disengaged from the piston with the barrel installed. The link is too long and won’t allow us to move the cocking shoe to the enlarged slot in the spring tube for removal.

Taking off the barrel is not hard. The pivot bolt nut comes off and the pivot bolt can be unscrewed from the spring tube forks. Once the bolt is out that barrel separates from the spring tube. Now the cocking shoe can be removed from the spring tube, and that frees the piston to be removed.

Now the gun is ready for the Vortek center-locking air piston. It’s as long as the Weihrauch piston we just removed, plus there is the white plastic spring guide in the rear.

Vortek CLU Beeman R9 two pistons
The stock piston above the Vortek CLU and its guide.

I haven’t said anything about the Vortek piston seal yet. It’s impregnated with moly, so no lubrication is required. It covers the fill port where the air is pumped in, and it just snaps in place.

Now I slid the Vortek CLU and spring guide all the way into the spring tube. Once the ridge in the center of the flats on the CLU is aligned with the center of the cocking slot, the cocking shoe and cocking link can be installed in the spring tube, where it engages the Vortek CLU.

Barrel goes back

Now the cocking shoe is inserted in the spring tube to connect with the CLU. I greased the bottom of the shoe with moly paste before installation. Once it’s in, the barrel is reconnected with the spring tube and the pivot bolt and nut are tightened.

Vortek CLU Beeman R9 unit in
The CLU is all the way in the spring tube with the spring guide sticking out behind. There is room to install the end cap.

End cap in

At this point, the end cap goes back in the spring tube. It slide in almost all the way, and stops when it contacts the end of the spring tube.

Vortek CLU Beeman R9 end cap back in
End cap slides in almost all the way. A spring compressor has to push it the rest of the way.


As you can see, the end cap goes back in the spring tube almost all the way. A mainspring compressor is needed to push it all the way in. I used the Air Venturi Rail Lock compressor.

Vortek CLU Beeman R9 compressor
The mainspring compressor has to push the end cap in the rest of the way.

Once the end cap was in I rotated it so the locking flange aligned with its slot, then I tapped in all 4 tabs. The compressor was removed and the safety and trigger went back in. Remember to cock the trigger before installing it, to make it easier to align the pin holes.

The barreled action then went back into the stock and all bolts were tightened. Time to test. The rifle cocked and fired the first time, so everything works as advertised. I’ll give you a detailed performance report next time.

How long and how difficult?

This job took me one hour, start to finish. The hardest part was getting the R9 apart. Those pesky tabs were new and resisted removal for about 25 minutes. Other than that, this was no more difficult than replacing batteries in a flashlight. More things to do, certainly, but no more difficult. I’ve done this sort of thing many times, though, and I have the right tools, which include a pin punch set, a plastic hammer, a mainspring compressor and a small Allen wrench.

Remember I also had to compress the CLU, which took a hand pump. The adaptor came with the unit, but a high-pressure hand pump was required.


The beauty of this unit is if I don’t like how it shoots, I can disassemble it and change the pressure in the unit. I will show that in a future report.

Next I will test the velocity as it stands right now. Pyramyd AIR sent me samples of every .20 caliber pellet they sell, so we have the whole field to test.

I will also be testing accuracy down the road, although that isn’t the focus of this report. But, as long as I have the R9, why not?

60 thoughts on “Beeman R9 with Vortek center-latching air piston: Part 1”

  1. B.B.,

    I have a .20 cal. R9 that I purchased new about 5 years ago, and it is still factory stock. I never have shot it too much because it was not a smooth shooter. Accurate, but more jarring than I like. I also have HW95’s in .177 and .22, which are also factory stock, but they are quite a bit smoother, just a bit of spring buzz. This new product may be a good excuse to for me to remedy my .20 R9, if it does what it’s suppose too in your test.

    By the way, for reference my .20 cal. R9 shot the best with JSB 13.73 gr. domes. I don’t remember chrony numbers, but if you would like them for comparison to a stock spring gun with “low mileage” I can get it out and shoot a few strings. I still have a good supply of the different .20 cal. pellets I was testing. Just let me know.

    David H.

  2. B.B.,

    I wonder how difficult it will be to disassemble now that it has a gas spring in place for adjustment? The gas piston that is center latching looks like a drop in unit for any spring piston as that unlike a regular gas piston which usually latches on the piston body. This will not require significant re-engineering to change the sear location in the course of conversion.


    PS: Section Spring guide Third sentence: “He had my (me) put the white plastic spring guide on the tail of the piston and then press down.

    Section Piston Third paragraph Second sentence: “It’s (like) as long as the Weihrauch piston we just removed, plus there is the white plastic spring guide in the rear.”

  3. BB
    Will there be other guns this gas spring will be available for in the future or just this gun?

    And definitely like the tunability. Just think no spring noise or vibration. I can think of multiple guns I would like to try one in.

    And kind of glad you are doing a .20 caliber. Don’t see many tests nowdays on that caliber. I still have yet to own a .20 caliber. Don’t know why. Just never tryed them yet.

  4. I am not familiar with gas pistons and have not studied them or their operation. From what I gather:

    -The white guide is fixed and does not move
    -As the barrel is cocked, the piston is pushed back against the white guide
    -The white guide then goes up into the piston and compresses the air charge
    -The center latch rod then engages the trigger mech. and is locked and ready at this point

    -Upon firing, the entire piston assy. is launched forward, compressing the air in front of the piston and launching the pellet

    -Based on the pre-load that required a spring compressor,… the white guide is maintaining about 1/2″ of compression on the piston

  5. BB,

    I am really looking forward to “the rest of the story”. For quite some time now I have wanted to adopt an HW95. When you add in an adjustable gas spring, this will likely turn a nice air rifle into a superlative air rifle.

    The adjustable gas spring is what I have been dreaming of. The ability to readily adjust power on a sproinger is what has been needed for some time, most especially with all these uber magnum sproingers everyone wants to build. I have been wanting to tune down my Tomahawk to a less jarring level to see how it will perform. To be able to tune your sproinger to a particular pellet will be awesome.

    Please do not drag this out too long.

    • RR,

      I don’t plan to drag it out, but I do plan to test the unit several different ways. Like I said — I’m not really interested in the accuracy. I assume that’s there. I’m interested in the performance and how I can control it.


      • BB,

        That also is where my interest lies. I do hope that they will be bringing forth other models in the near future. This is another big step forward in the world of airguns. Now if we could just keep these out of the hands of the speed freaks.

        • RR
          Yep soon as they start turning them up they will start tearing their guns up. Then the bad reports will start rolling in.

          I agree. This is another big advancement in the air gun world.

  6. Hi BB,

    Those end cap tabs are easier to get out if you can take the load of the spring with the compressor first. Think I read about that trick in Airgun World .



  7. David H ,

    Put some Tune in a Tube on the mainspring guide and that buzzy R9 will calm right down. Weihrauch doesn’t use enough grease on the spring guides. On the newer guns that come through the tech department for any reason we grease the guides, it has really cut down on our returns. The 5mm is a great caliber.

  8. BB ,

    Thank You for showing the burnt seals from a RX. In spring guns it is all about piston velocity. If the piston goes forward too quickly the parachute seal wont open up . I like how this unit can be filled to different pressures, this way someone can make there gun a 12ft lb unit for plinking and then hop it up for hunting. Nice to reduce pressure for the youngsters too !!

  9. Ok I guess this is going to be another remedial question, but as they say the only remedial question is the one you don’t ask. Why isn’t the spring itself the stationary part pushing a lighter piston to compress the air. It seems this would reduce perceived recoil. Does it have something to do with the mass of the spring enhancing the compression?

    • Carl,

      I think the answer is yes. You do need some mass to push the air out of the compression chamber, because the pellet sits in the breech and resists as long as it can.

      I remember years ago shooting a TX200 Jim Maccari had tuned with a custom-made plastic piston. It was supposed to do just what you said. But what it actually did was vibrate so much it was painful to shoot. The vibration might have been the piston bouncing back and forth off the compressed air cushion, rather than a sideways vibration.


  10. Gene beat me to it. This is also far superior to having a box full of springs or clipping or scragging or finishing ends and perfectly greasing and dont even mention “tightening internals”. I never found that to be the fun part… Although my lower powered springers responded well to a binding tune.

    I am elated to see this product and think this will help the high-end spring gun market especially with the pcp “movement” There are guns that can be settled with just a small decrease. this will be very fun for some people. ( me included I’m especially thinking of my Diana 36)

    I guess the hw95 just jumped back to the top of my short list. Although I will be dusting off my marksman70 off when I get home. I doubt this will be compatible but I gotta look.

    • forgot to mention I think RR nailed with tuning it to a specific pellet. I think that is as game changing as a power adjuster on a pcp. (maybe, we’ll have to see)

  11. B.B.

    What an interesting report! I can not wait for part 2. I hope it works better than anticipated. Can this also be used in the HW 30, 50, 77, 97? They all have the same piston diameter?

    “Once the end cap was in I rotated it so the locking flange aligned with its slot,” This was done with the compressor in place I assume? Was it hard to rotate it because it is under tension?



    • Yogi,

      First — yes, Vortek does have an R7/HW 30 unit operational. In fact, they wanted me to test that one, as well.

      Next, it wasn’t too hard to rotate the end cap. I hit it sideways with a screwdriver blade driven by a hammer. Just a light tap, because the face of the compressor is a Nylon tip. So the end cap rotated easily. It was harder keeping the tip of the compressor rod on the end cap as I wound it down. It wanted to walk off. But again, light taps with a hammer.


      • B.B.
        Thanks for the reply.
        One of the joys of a springer is no extra stuff! If I need to buy a high pressure pump now, almost defeats this purpose. Any other way to fill the ram?


          • B.B.

            Interesting project! Easy to follow for someone who only ever dealt with a springer pair of Marksman Bikeathlon rifles.
            Since you used a pump to do the 8 or 9 pump strokes (with a guage? I suspect.) to fill to a set pressure why wouldn’t you be able to use a HPA cylinder with a guage? You wouldn’t need any more than a smallish cylinder, on off valve with pressure bleed, microbore hose and a inline pressure guage; or if you have it a gigantic CF cylinder with 4500PSI as long as you were real careful not to over pressurized it!!!!
            With that said; a question, how do you depressurize the gas strut? The fill adaptors must have a check valve…must it not?


                • Siraniko,

                  That looks like it could be what he is talking about. I had hoped it was a different gun though. Back in the late ’80s I bought my daughters each a “Biathlon” style springer. It had peep sights, a hooded front sight, a pistol grip and it was low powered. I remember that the stock was blue in color on at least one of them, but I can’t recall whether it was painted wood or plastic. I hadn’t been into airguns long myself at that time and didn’t pay that much attention to the gun. It was just a cheap, light gun aimed at youths that I thought would be a good way to see if they developed an interest in shooting. My oldest became interested mainly because she could torment her boyfriend with how much better she shot than he.

                  I was hoping this was the gun, but I don’t think it is. Thanks for the link.


      • BB
        Oh no don’t even tell me that about the kit for the hw30. I been doing real good to not get inside the one I have. But it would be interesting to see what kind of difference it would make.

      • B.B
        Here’s my solution to the walking problem. My homemade rail lock compressor uses a bearing with a 1/4 bore that uses a brass rod for Crosman style end caps with the hole, or a plastic golf tee for end caps with no hole eliminating any chance of walking and of course it’s adjustable height.

  12. Love the concept, B.B.! If user-replaceable seals were made available (or could otherwise be obtained from an online o-ring supplier or 3D printed, for example), it would eliminate my wariness of gas spring air guns. (I don’t own any of them, myself.) I don’t share your appreciation for them, because every automotive gas spring hood or hatchback strut that I’ve ever owned has required replacement. In fact, the OEM springs under my 2004 Ram 1500 pickup hood are overdue for replacement right now and, in my experience, automotive gas springs don’t usually even make it to 14 years.

    • Cal
      This is a little different. These are filled with compressed air. Not gas or oil like struts.

      This “air ram” that BB is reporting about today should last for a long time I’m thinking.

      • I just like the ability to rebuild my guns and related accessories, Gunfun1. Out of dozens of o-rings in my Hill MK4 hand pump for instance, there are two o-rings that need frequent replacement. One of them is even a low pressure stage o-ring (the upper outer slide tube ring). The other one is the o-ring in the output check valve. Strangely enough, the tiny green o-ring in the high pressure stage never needs replacement!

        • Here’s more info for any Hill MK4 users who stumble upon my comment, above: An uber expensive perfluoroelastomer / FFKM o-ring (something like $10) significantly mitigates frequent check valve failures. Similarly, I’ve found that an Aflas / FEPM o-ring lasts longer than the OEM o-ring as the upper slide tube seal. Hill Tech Support and I believe that the check valve o-ring is sometimes damaged by detonation but I never see signs of it with FFKM. In the other failure case, the upper slide tube o-ring begins to leak as it rather rapidly takes on a compression set. Aflas can be somewhat more resistant to set than OEM (FKM?) so it works well there. As far as I know, both FFKM and Aflas must be purchased in the closest AS568 (‘merican) size vs. the OEM metric. They are actually slightly fatter in cross section than the metric OEM rings and this helps with the slide tube problem as well. A U.S. Mil-spec FKM slide tube o-ring is my second choice for the slide tube.


          • Cal
            True about the option to rebuild if needed.

            But I’m thinking this air ram will last a long, long time without needing any rebuild or replacement.

            I’m thinking the air ram should last as long as a steel spring if not longer before any failure happens.

            • Myself, I would need to believe that it will somehow last a few times longer than a steel spring (with or without low-cost rebuildability) to buy it, but I am very interested in it, nonetheless. Steel springs are cheap and simple to replace and, yes, they seem to typically last for only around 10,000 rounds or perhaps 30,000 at the extreme. 10,000 pellets may be a lot of shooting for most people (a decade?) but it’s only 20 tins and a devoted airgun enthusiast will shoot that much in about a year. I hope my life will soon permit me to shoot my springers that much (and maybe get myself committed and devoted to Field Target)! I’ve paid $15 to $20 for both OEM and aftermarket springs in the past and $30 seems to be the upper end for spring replacement costs. I suspect this air piston will greatly exceed mechanical spring prices.

              • Cal
                I shoot alot too. And that would be the thing about the air ram. It would take some time to see how it stands up.

                But I have to say I would choose the air ram over a nitro piston any day.

  13. Innovation is a good thing. But I wonder if there is such a thing as too much adjustment or at least a point where you get diminishing returns. The adjustable custom gas system for my M1 Garand really messed it up and has taken 10 years to understand and fix. And I find that I do not make use of most of the adjustment on the stock of my Anschutz target rifle. With a few minor tweaks, it has worked fine.


    • Matt61, What was the problem with your Garand? I have Schuster nuts for all three of my Garands and they have all worked as advertised for me. They permit me to shoot commercial ammo or hotter than military hand loads (though Greek HXP seems to be pretty hot to me!) while getting better than military ammo accuracy. When I shoot John C. Garand fun matches, the Schuster nut is easily replaced with the original gas nut.

      • It’s a long story whose details would probably bore many of the readers. I had a custom gas adjustment installed for handloads with IMR 4064 powder. But it needs to be very carefully adjusted for different loads and the set screw that adjusts it seems to move on its own. The guy who designed it retired and went incommunicado without warning, so I had to figure it out by myself with some help from the blog. It’s working now, but it was a difficult learning experience.


  14. B.B.,

    I don’t see a reason why you can’t do away with the microbore hose entirely and simply stick the piston’s fill adapter into a female Foster fitting with a proper adapter attached directly to the outlet of a hand pump. That would eliminate a lot of the dead space and therefore give a better reading on the actual pressure you are putting into the piston.


  15. My .20 R9 was purchased from PA February of 2018 and currently has about 1500 pellets through it, so the velocity has stabilized. It slightly buzzy, but not very hold sensitive. It will shoot sub half inch 5 shot groups at 30 yards. ( I’m a hunter not a paper puncher).

    I can get you specific numbers if you’d like, but I will post a rough fps average here.
    11.42 gr FTTs avg 775-790 fps
    13.73 gr JSB avg 700-710 fps
    13 gr polymath avg 690-700 fps
    13.27 grain baracuda 695-705 fps
    14.3 grain benji cyl. 670-685

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