Rebuilding a Hatsan...
 
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Rebuilding a Hatsan Vortex Gas Ram  

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SteveP
(@stevep)
Joined: 3 months ago
Posts: 40
September 24, 2020 13:19:03  

I've seen the question asked on more than a few forums, "Can a Hatsan Vortex gas ram be rebuilt?". While I've seen the Mike Ellingsworth video on Youtube where he got inside one and did a basic description of the ram and pieces of it, he never got totally in-depth. Also been a few years now since I saw where someone in the UK did but haven't been able to find his post again.

Having several Vortex rams in the parts bin, one of those from a Hatsan Model 95 .25 cal I blew the seals out of tinkering with higher pressures, I dug it out, grabbed a camera and decided to tear mine down, see what's in there and take some measurements. I may have to split this into 2 entries for all the pics taken and I haven't decided yet whether I'll actually rebuild it, but I have everything I need to. Whether anyone else does after reading this is totally up to them but at least the information will be out there should anyone want to look for it.

On that note, here's the Vortex ram in question. By the printing on the tube, it's a Hatsan Type 1 ram and clearly states 150 bar max pressure. They usually come somewhere between 120-125 bar new and that pressure can be raised with a Hatsan fill probe and a high pressure hand pump or lowered by tinkering with the bleed screw. 

Vortex ram body

I'll start on the back end which in Mike's video, he said he'd already drilled and milled I'm guessing to fit an aftermarket ram in the rifle. Here's what that end cap looks like untouched. The forks for anyone who doesn't know are where the Quattro trigger pack slides up inside the receiver. It also has the fill hole for a Hatsan probe, a bleeder screw with what I believe is a Delrin o-ring to seal it and 2 o-rings on the outside of it. It turns counter clockwise to remove it and you can use a flat tip screwdriver between the forks or in my case, I slid a phillips head screwdriver in the fill port. You'll see the threaded part is fairly long so it will take you some between that and the 2 o-rings they use to seal it. It's also, as far as I can tell, 1 solid piece and I have no clue how they pulled off the fill and bleed porting so maybe someone who knows that kind of stuff can chime in on how it may have been done

Both of those o-rings are the same size and measure as follows: Width 2.5mm, ID 11mm, OD 16mm.

Bleed port and screw for it. 

Vortex bleed screw 2
Vortex bleed screw

Fill port. On at least the Model 87 and up, Hatsan has a hole in the receiver for sliding a fill probe in and another for access to the bleed screw so removal of the gas ram isn't necessary if you decide you want to tinker.

 

Vortex rear cap 2

Threading and where the 2 o-rings are. In the 2nd pic, they've already been removed but easy to see where they sit.

Vortex rear cap 3
Vortex rear cap 6

Interior view of the rear cap to show fill port.

Vortex rear cap interior

Part 2 of this in the reply to my own thread...lol


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SteveP
(@stevep)
Joined: 3 months ago
Posts: 40
September 24, 2020 13:41:38  

Now for part 2.

My ram was already shot and empty of any pressure before I removed cap and I should have said that in Part 1. Once that rear cap is unscrewed, you can now just push and the piston shaft will side out the back of the ram body.

In Mike's video, he mentioned an o-ring under the allen head screw. I took that screw out thinking I'd likely have to replace that o-ring to find there isn't one. That "o-ring" is actually a lock washer. I'm guessing they used it to keep that allen head screw in place but at least on mine, they had no worries. It took quite a bit to actually get it loose, then get it unscrewed. While I saw nothing to make me think they used any kind of threadlocker on it, it was seriously NOT going anywhere.

The screw is just big enough to stop the shaft from coming totally out of the ram and I would have thought there would be an o-ring under that screw to seal the shaft but at least on mine, there isn't one and it makes me think there isn't one on the piston shaft Mike shows in his video.

Here's the pics of the shaft, screw and lock washer. That screw uses a 3mm allen wrench should you decide for whatever reason to take it out.

Vortex piston parts 1
Vortex piston shaft and allen screw
Vortev piston shaft lock washer

That brings me to the brass front cap/shaft guide. You'll need an 18mm box wrench or similar and heat to get this thing off. The goop you'll see in the pic of the tube end is actually blue and some kind of thread locker for that cap and you'll need a heat gun to get it loose enough to break that cap loose and unscrew it. You can see where the outside o-ring sits just below the lip of the cap.

Vortex brass end cap shaft guide
Vortex front cap threading

While the picture of the inside is really not that great, the 2 darker bands the red arrows point to inside it are o-rings. As far as I can tell from what I'm seeing, those 2 o-rings are the only things keeping the air sealed in the ram and may likely be why at some point, the Hatsan rams fail. Constant use has to wear them down until at some point, they start to let air bleed out.

They're also a major pain to get out of that cap. There's also one on the outside at the top of the threading which seals it to the ram body and is the same size as the 2 on the rear cap. Those seal sizes are as follows:

1 outside - width 2.5mm, ID 11mm, OD 16mm
2 inside - width 2mm, OD 8mm, OD 12mm

Vortex brass shaft guide 1

Heat aka a heat gun is your friend should you decide to try this, especially as already mentioned on that front cap. 

Feel free to ask any questions or if there's something you want a better pic of, as and I'll try and take one and hopefully I've covered fairly well everything to do with a Hatsan Vortex gas ram and what it might well take to rebuild one.


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SteveP
(@stevep)
Joined: 3 months ago
Posts: 40
September 24, 2020 13:50:13  

Before I forget and I was about to, Part 3 which takes me back to that rear cap. 

I also have a Hatsan Type 3 ram that came out of a Hatsan Edge Vortex. The only differences I see between it and the Type 1 are the printing on the tube to denote Type 3, the rear cap which is made to fit the Edge/Striker/1000X rifles and doesn't require the forks as the triggers in those are attached to the bottom of the receiver and while it has a fill probe hole, it doesn't have a bleed screw. I haven't tried to degas it yet so I'm not entirely sure on how to go about it, but the guess is anything that could be slid in there to depress the valve and let the air out. 

My guess and probably a very good one is that should I want to, I could degas the Type 3, unscrew that rear cap, screw the rear cap for a Type 1 on it and have a ram that would fit in the Model 87 and Model 95 rifles.

Vortex type 3 print
Vortex type 3 ram 1

 


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marflow
(@marflow)
Joined: 3 years ago
Posts: 1000
September 24, 2020 15:20:08  

when you took a Hammerli  850 valve apart the suggested way to seal it back up was with Teflon pipe thread sealer, so that might be an option here 

and if i were to be rebuilding many of these, this tool would be my choice 

https://www.google.com/search?ei=Ju9sX8bTLJb6-gSw1YPIAg&q=3%2F8+butterfly+impact+wrench&oq=3%2F8+butterfly+wrench&gs_lcp=CgZwc3ktYWIQARgAMgYIABAWEB4yBggAEBYQHjIGCAAQFhAeMgYIABAWEB4yBggAEBYQHjIGCAAQFhAeMgYIABAWEB46BQgAEJECOggIABCxAxCDAToFCC4QsQM6AggAOgUIABCxA0oFCAkSATFKBggKEgIyMFDBnRNY9OsTYLSLFGgAcAF4AIABWogB-gmSAQIyMJgBAKABAaoBB2d3cy13aXrAAQE&sclient=psy-ab

pick brand and with the bit, should a guess hex or allen, you state box, which is just an open end wrench, little will be needed 

just some ideas 

check out the O"ring Store for o'rings, the service is first class 


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SteveP
(@stevep)
Joined: 3 months ago
Posts: 40
September 24, 2020 16:05:33  

Basic hand tools, a crescent wrench in place of the open end wrench, o-rings and an o-ring pick and some silicone to lube those o-rings with is all you really need besides the Hatsan fill probe and a hand pump and I have it all.

I posted as it's info I've seen asked about but never saw any real answers to in the 5 years I've been back shooting. You could just as easy save all the work, get a new one from Hatsan or convert it to a real springer which just takes getting the right end cap from Hatsan (the gas ram and spring versions use different end caps) along with a spring and guides.

For those who like to tinker, now you know what's in there 🙂


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marflow
(@marflow)
Joined: 3 years ago
Posts: 1000
September 24, 2020 21:13:17  

thank you for the post 

many of us have to figure out how to fix thing, airgun or not, with the tools we own, knowing that other tools can make it easier 

so how do i justify buying tools, i'm a guy and tools are a good investment, that is my brain says 

sometimes you just have to make a tool, just part of the game 

and why not buy another one simple, what fun would that be 

please tell us how the repair goes 

take care 

mike


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SteveP
(@stevep)
Joined: 3 months ago
Posts: 40
September 27, 2020 09:44:46  

The hand tools used were basic ones most people have around their house anyway and airgunners?? Yeah, we got tools that in some cases can't be used for anything but our guns...lol. The only real expense for someone wanting to potentially try this and not having them, is a high pressure hand pump, the Hatsan fill probe with adapter and those 5 o-rings.

In my case, I already had them and actually bought mine quite awhile before I bought my first PCP just because I already was tinkering with the Hatsan rams. My tinkering is like anyone else's and from where I'm sitting, no different than anyone who buys a new PCP or springer, looks at it and thinks "Well now, what can I do to wring a bit more power, better shot curve, stick a reg in, get a smoother, quieter shot cycle" or any number of other things.

Will it be worth it?? Maybe? If nothing else, it's a bit of information shared with air gunners so if they're considering, they have a better idea what they're up against and sharing knowledge is never a bad thing, least not to me 🙂


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SteveP
(@stevep)
Joined: 3 months ago
Posts: 40
September 28, 2020 14:30:33  

As of typing this reply, my rebuilt gas ram has been sitting on my shelf with 120 bar in it for 3 days now and appears to be holding fine. New o-rings got installed where needed, tube cleaned and re-siliconed and to see what would happen, I replaced that lock washer on the piston shaft with an o-ring.

new rings 1
new rings 2
new rings 3
finished gas ram

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Final thoughts:

If you'd asked me 3 or 4 years ago if doing something like this would be worthwhile I would have said yes. Back then, hatsan refused to sell gas rams so if yours went, you were stuck with either no rifle or converting it to a spring. Doing all this and posting about it at least gives owners a way better look at a Vortex ram inside and out and what would be involved in rebuilding one and for me, it's been fun tinkering and learning what's involved with them. 

Would I do it again? Nah. The Model 95 that ram came out of was converted quite awhile back to a spring version when a member of another forum sold me an already tuned 95 springer as a parts rifle. All I did was install my .25 cal barrel on it, put it back in the already refinished stock and go back to shooting.

Nowadays, Hatsan, although pricey, will sell you a brand new gas ram for something like $44.95 plus shipping. Just fill out their form, tell them which model rifle and in a few days to a week, your new ram will get delivered to your door. You can still tune a gas rammed rifle, just no spring to deal with and should you choose to tinker with the ram pressures, everything I laid out doing the rebuild will help with that should you want to mellow one out a bit.

There's also the option of doing the same thing only telling Hatsan which model rifle and that you need the parts to convert it to a coil spring piston rifle. You'll need a different end cap as they are different between the ram and spring versions, along with of course the spring, spring guide and tophat unless you want to make your own and have the necessary stuff. While you're ordering, I'd also go ahead and get new seals and do a full tune.

Hopefully my time and tinkering helps someone out there debating what they want to do and I very much enjoyed myself doing it. If you've read this far, thanks for taking the time 🙂 

 


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marflow
(@marflow)
Joined: 3 years ago
Posts: 1000
September 29, 2020 15:34:01  

will it go back in a gun or was this just to see if the ram and you could get along 

tinkering make us better mechanics and I'm all for it 


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SteveP
(@stevep)
Joined: 3 months ago
Posts: 40
September 30, 2020 12:12:00  

Both actually...lol. I still have the Hatsan 95 it came out of. Was my first rifle getting back into air guns 5 years ago so one I kept after selling off a few rifles. Also have a couple other Hatsan  gas rammed rifles in the small herd of guns I still own so I have a spare should I need one.

The 95 it came out of before and after refinishing the stock:

Model 95 before and after

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marflow
(@marflow)
Joined: 3 years ago
Posts: 1000
September 30, 2020 17:53:12  

that is a nice stick of wood, i put it in my photos to enlarge and great grain angle in the grip area 


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