Hatsan Jet I/II Discussion

[Rat Sniper (AKA: PaulT58)]

Yep, I like the compactness of it and LOP is good for me.  As James pointed out, great for tight places!

The only thing I did was add a "D" ring to attach a sling.

[naptemp]

I have a Jet 2 in .177.

I slightly flattened my shot string by:
-removing the 2 hammer spring preload washers
-adding 2 M3 nuts as preload to the valve spring

Now I get 4 magazines (32 shots) from 250-260 bar to 160-170 bar, between 780-820 FPS  with 7.5 grain pellets.

I am not sure if changing to a weaker hammer spring and a stronger valve spring would help too much at this point.

With my .177 Jet 2 I have managed to get 6 magazines (48 shots) with 7.5-8 grain pellets in the 740-780 FPS range from 250 bar to 130 bar.
These are the mods:
-removed the 2 hammer spring preload washers
-added 1 M3 nut as preload to the valve spring
-placed 1 washer on the valve stem where the valve spring sits
This washer will restrict the air flowing into the barrel, and also acts as valve spring preload.
Initially the washer was restricting most air and got velocities in the 400 FPS range.
I ground the washer outer diameter a little to allow more air to pass.

[JPSAXNC]

That's excellent John, I'm glad you figured out how to tune it.

[naptemp]

That's excellent John, I'm glad you figured out how to tune it.

The FPS is in the 740-780 range but it often jumps up and down 10-30 FPS.
I am not sure what the cause is.
Without those jumps I could probably get a 30FPS spread.

[fixit]

I recently got a .25 jet 1, and I have been stunned by the absence of info concerning dis assembly.  Mine leaks like so many of the others, and I would just as soon repair it myself. Any suggestions?

[naptemp]

I recently got a .25 jet 1, and I have been stunned by the absence of info concerning dis assembly.  Mine leaks like so many of the others, and I would just as soon repair it myself. Any suggestions?

I used this post to get to the hammer spring:
https://www.gatewaytoairguns.org/GTA/index.php?topic=204810.msg156400319#msg156400319

I could not find photos on how to disassemble the valve and air cylinder, but it is actually easy and I am not an expert in any way.

[ModFox]

I recently got a .25 jet 1, and I have been stunned by the absence of info concerning dis assembly.  Mine leaks like so many of the others, and I would just as soon repair it myself. Any suggestions?

I put 200 pellets thru mine and now I'm joining the Jet 1 Leak Club. I fixed mine easily by having a second jet. I found the first had leaked out all of the air and would hiss out of the barrel when trying to fill. So I got out the second new Jet to test my new BuckRail supressor (great for 35$!)

Somewhere along the way I swapped a charged barrel back into the original now hissing Jet, and had put a drop of Lucas Gun Oil into the silver foster valve opening trying to get at that tiny o-ring. Maybe 2 drops there. Also a tiny amount on the treads of the tube. Very tiny. WHEN I swapped the charged tube (approx 12 bar) into the hissing Jet it held air, then began to release it very quietlt and slowly about a minute later. So Tried pumping, and the loud hiss came back fully. I figured I was onto something so i put a drop on the silver tip inside the tube for redundancy and recharged that tube into the green using my other Jet. I diligently put about 5 drops of gun oil into the small hole on the male threaded valve block of the hissing gun (not the tube, the small hoffset hole on the protruding reciever interface). I made sure those drops got down inside with a lil plastic piece. Lucus moved itself down there nicely with its own self cohesion, I drive every car I own to 300K miles using Lucas products and sell them driving just fine, so definitely Lucas for my gun.

Anyways when I put the charged tube on, the pressure pushed everything into place apparently and its currently holding air.

[ModFox]

Yep, I like the compactness of it and LOP is good for me.  As James pointed out, great for tight places!

The only thing I did was add a "D" ring to attach a sling.

After building out that bigger monstrosity I realized that while it makes a great fit for the range, its not near as good for packing as the original. So I went the opposite direction...

I cut an arrow in half, fit the two of them into the upper buttstock reciever port, and am happy with the initial result. It needs a rear swivel and pad, but its ultra ultra light and still gives the aiming support needed for a good carbine shot. A single larger tube would maybe be better but the two arrows worked well enough to ensure I will build something for the general concept.

[naptemp]

I recently got a .25 jet 1, and I have been stunned by the absence of info concerning dis assembly.  Mine leaks like so many of the others, and I would just as soon repair it myself. Any suggestions?

...
So I got out the second new Jet to test my new BuckRail supressor (great for 35$!)
...

I 3D print my suppressors and they cost around $1.
It takes 6 to 10 hours to print a quality suppressor, so I do it over night.

[ModFox]

I 3D print my suppressors and they cost around $1.
It takes 6 to 10 hours to print a quality suppressor, so I do it over night.
[/quote]


What printer do you use?

[naptemp]

I 3D print my suppressors and they cost around $1.
It takes 6 to 10 hours to print a quality suppressor, so I do it over night.

What printer do you use?
[/quote]
i have a Anycubic Kobra.
I am sure there many other 3D printers just as good.
You need to know how to use it.

[ModFox]

i have a Anycubic Kobra.
I am sure there many other 3D printers just as good.
[/quote]

Thats my price range and seems legit. I was going to get the cheapest one on Amazon for about 150 but the Kobra seems good. I want one large enough to print Jet buttstocks and shrouds, I'll have to look closer.

The Buck Rail was kinda an obvious economy choice not having a printer and wanting decent supression asap. I also really wanted to know how welll they work for comparison.
 

[naptemp]

Thats my price range and seems legit. I was going to get the cheapest one on Amazon for about 150 but the Kobra seems good. I want one large enough to print Jet buttstocks and shrouds, I'll have to look closer.

The Buck Rail was kinda an obvious economy choice not having a printer and wanting decent supression asap. I also really wanted to know how welll they work for comparison.
 

I 3D printed some stocks too.
Usually they are printed in smaller parts and sometimes you need to glue them together.

[ModFox]

Anyone ever shoot the .25 Umarex Brimstone Pellets or the .25 Dead Centers with their Jet? I found the Grizzly slugs were awful, I mean REALLY awful, so I'm looking to try some heavier pellets.

What other .25 heavy pellets might be good? FX Airguns brand?

[Back_Roads]

Anyone ever shoot the .25 Umarex Brimstone Pellets or the .25 Dead Centers with their Jet? I found the Grizzly slugs were awful, I mean REALLY awful, so I'm looking to try some heavier pellets.

What other .25 heavy pellets might be good? FX Airguns brand?

Air Arms, H&N Hunter, Poly Mag, NSA slugs, all work in mine

[fixit]

Well, I got around to tinkering with mine, and it really is simple in construction! All I did with mine is to clean out the debris, which was everywhere, lube with silicone grease, and re assemble.....no more leaks, for now! Here's hoping for no further problems.

[SophusLie]

Wonder if a guy could buy a half dozen or so of those foster caps?

Foster Caps

Here’s a lifetime supply --- 200 caps --- for 5-1/2 cents each.

Can't post hyperlink ?  Amazon ASIN B08HLZZR89

These are black vinyl screw protectors with a nominal 7.5mm ID.  A Foster quick- connect plug has a nominal 8mm OD.
Vinyl screw caps need to stretch to fit, otherwise they will fall off.
On the above, I like to scissor-off about 2mm from the open end to eliminate extra space.
Red caps are also available.

[SophusLie]

Let me try again

www.amazon.com/dp/B08HLZZR89/

[ModFox]

Got mine torn down... barrel removed, handle removed, etc. Love this gun. It will be apart for a lil while so if anyone wants any closeup pics of parts or design lemme know.

[Back_Roads]

 I use tire valve caps for foster covers