Hatsan 21" Jet barrel upgrade

[WOW]

So. The Jet is my muse. Made a bullpup and sniper rifle, and am into barrel swapping. This particular post is to ensure people that a smaller outer and inner diameter barrel is usable in the Jet. Obviously a larger one can be sanded down but a smaller one leaves a gap that needs attention. I will post a thorough video walk through soon. The barrel enters the suppressor for a few inches before bottoming out. Fits snug, no clipping, held by 4 grubs.

This barrel is a .22 cal from my Crosman 3622, which needs a longer barrel itself to be able to accommodate suppression. Could that longer one be a .25? We shall see. The original .25 Jet barrel is now reworked via drill-lathing to fit in my .43 cal T4E Walther PDP. That's a complicated and challenging mod, which is the point. This Jet longbarrel mod is much easier and just takes some creative latheing with a drill and some well placed o-rings. Particularly the bolt on the Jet doesn't have an o-ring, it's inside the barrel and isn't in Crosman barrels. Have to reshape the bolt and add a notch for an o-ring just like the Crosman bolt, and it works really well. Just gotta fine-tune the clearances and ensure the rifling isn't an issue at the interface.
This one is a success at approx 21 inches, but I have a 14 inch laying around somewhere and will likely make a video starting from scratch with that one for YouTube's sake.
Need to chrony this mod so as to ensure legal compliance in IL. Over 700 fps and it needs registered, so I'll likely be taking this apart again once I get a rating. The Crosman 3622 does basically the same thing but just isn't as modular.

My creative muses:
Jet 1 .25 cal
3622 .22 cal duh
Walther pistols .177 and .43 cal

The one I won't mod is ironically called a Mod, the Hatsan Mod 65 .25 cal springer. My perfect gun, always ready to go while all of my other stuff is on the bench in pieces. It's a real sweet spot for springers and the wood stock design is paramount. Heavy tho.

Please don't diss me about my projects. Thanks. Constructive criticism only. We all know you can go buy other, better guns.

 

[OneAcreFarmer]

I like it. I too like to mess around with cheap stuff. I don’t have the budget to mess with high quality pcps and I like to tinker.

 

[WOW]

I like it. I too like to mess around with cheap stuff. I don’t have the budget to mess with high quality pcps and I like to tinker.

Thanks man.
If I bought a 2,500$ gun it would be in pieces within a week anyways lol

 

[WOW]

Update: got a chrony and measured the mod w the .22 long barrel... the shot string peaked in the 690s, near perfect for me. Some air is escaping out of the rear and I was hoping it was enough to keep the fps below 700. Nailed it! Installing another oring to snug up against the back of the barrel when closed will likely up the fps, so I'm not doing it for now. Also, the port I drilled into the barrel is smaller than the original by maybe 30%, so it would be another point to increase fps if I wanted to, which I don't, for now. Not sure if my moderator is slowing it down either but it's definitely quieting it significantly. Really happy I don't have to give up on this build for breaking 700fps.

Got a .25 cal Avenger barrel to play with a .25 long barrel Jet build and have yet to figure out how to install it without cutting it. It's very close to the Jet dimensions, but the oring channels likely need deepened slightly and it's just a smidgen shorter in the rear behind the port. Usable, but not with a magazine so I may be cutting off the port and making all new oring channels and a new port, again smaller than stock so as to limit fps. Upon doing this I will also be able to fashion a proper rear seat to hold a magazine.

I'll add a pic of the bolt for the .22 mod. The oRing isn't needed as I eventually spun down the bolt. Removing this oring ups the fps by about 30-40, which were the conditions under which it was hitting 690 with coppered barracudas. Adding it drops the fps by about 30-40 due to taking up space.

Luv this gun.

 

[Rick64]

So. The Jet is my muse. Made a bullpup and sniper rifle, and am into barrel swapping. This particular post is to ensure people that a smaller outer and inner diameter barrel is usable in the Jet. Obviously a larger one can be sanded down but a smaller one leaves a gap that needs attention. I will post a thorough video walk through soon. The barrel enters the suppressor for a few inches before bottoming out. Fits snug, no clipping, held by 4 grubs.

This barrel is a .22 cal from my Crosman 3622, which needs a longer barrel itself to be able to accommodate suppression. Could that longer one be a .25? We shall see. The original .25 Jet barrel is now reworked via drill-lathing to fit in my .43 cal T4E Walther PDP. That's a complicated and challenging mod, which is the point. This Jet longbarrel mod is much easier and just takes some creative latheing with a drill and some well placed o-rings. Particularly the bolt on the Jet doesn't have an o-ring, it's inside the barrel and isn't in Crosman barrels. Have to reshape the bolt and add a notch for an o-ring just like the Crosman bolt, and it works really well. Just gotta fine-tune the clearances and ensure the rifling isn't an issue at the interface.
This one is a success at approx 21 inches, but I have a 14 inch laying around somewhere and will likely make a video starting from scratch with that one for YouTube's sake.
Need to chrony this mod so as to ensure legal compliance in IL. Over 700 fps and it needs registered, so I'll likely be taking this apart again once I get a rating. The Crosman 3622 does basically the same thing but just isn't as modular.

My creative muses:
Jet 1 .25 cal
3622 .22 cal duh
Walther pistols .177 and .43 cal

The one I won't mod is ironically called a Mod, the Hatsan Mod 65 .25 cal springer. My perfect gun, always ready to go while all of my other stuff is on the bench in pieces. It's a real sweet spot for springers and the wood stock design is paramount. Heavy tho.

Please don't diss me about my projects. Thanks. Constructive criticism only. We all know you can go buy other, better guns.

View attachment 531219

What kind of velocity are you getting now with the longer barrel?

 

[WOW]

What kind of velocity are you getting now with the longer barrel?

My last text post goes into that, check it out. Short answer: about 690fps at 3000psi with coppered barracudas. Keep in mind that I personally am trying to limit it below 700, but there is a lot of room to play if the port were opened more or if the bolt were made to seal tighter. I can think of at least 2 further mods to gain fps... the bolt portion that fits in the barrel can be reduced in diameter further, and placement of the pellet deeper in the barrel "may" also give an increase. I know part of tuning it is pellet placement, but have yet to unlock the secrets of it or how it really affects velocity.

 

[Todywayne]

Nice... I'm new here, but not new to Airguns... I've been watching videos on the Hatsan Jet 2 in .25 caliber and will probably pull the trigger on one soon... That being said I already have a longer DAQ Barrel and an even longer Kral Puncher barrel, so I'll be doing the same mod too...!

 

[WOW]

Nice... I'm new here, but not new to Airguns... I've been watching videos on the Hatsan Jet 2 in .25 caliber and will probably pull the trigger on one soon... That being said I already have a longer DAQ Barrel and an even longer Kral Puncher barrel, so I'll be doing the same mod too...!

Nice. I think it's a great mod. Lemme know when u need them and I'll be sure to post some pics of my barrel lathing.

 

[Todywayne]

Nice. I think it's a great mod. Lemme know when u need them and I'll be sure to post some pics of my barrel lathing.

Sounds good... I appreciate that...!

 

[WOW]

Sounds good... I appreciate that...!

From my experience, I can say you'll want to get a BUNCH of orings. If you have a Harbor Freight they have e 225 pice kits in metric and SAE, I would pick up both for the 5 bucks each.

Glad you're into this man. Let's make this thread about seeing what barrels require what to install. I have an Avenger .25 I'm trying to fit, and this previous one was a Crosman .22. Really interested to see the results of your KRAL and DAQ barrels. What's missing from the test group would be the FX liners which I always wanted to play with. I know Walthers work but would love to get one into this group for comparison as well.

Regardless, you are going to LOVE the longer barrels because of the accuracy. Really great mod for this gun.

 

[Todywayne]

From my experience, I can say you'll want to get a BUNCH of orings. If you have a Harbor Freight they have e 225 pice kits in metric and SAE, I would pick up both for the 5 bucks each.

Glad you're into this man. Let's make this thread about seeing what barrels require what to install. I have an Avenger .25 I'm trying to fit, and this previous one was a Crosman .22. Really interested to see the results of your KRAL and DAQ barrels. What's missing from the test group would be the FX liners which I always wanted to play with. I know Walthers work but would love to get one into this group for comparison as well.

Regardless, you are going to LOVE the longer barrels because of the accuracy. Really great mod for this gun.

Sounds like a plan for sure...!

 

[WOW]

Sounds like a plan for sure...!

Harbor Freight orings are trash. Be sure to get quality orings. The ones at Home Depot are better.

 

[Avator]

I bought the oring kits at Harbor Freight and found 80% of the sizes to be useless for any on my airguns.. YMMV

 

[TerryE1]

I've got a .25 DAR barrel that I'd like to fit on my Jet1. But all I have is a standing drill press.

 

[WOW]

I've got a .25 DAR barrel that I'd like to fit on my Jet1. But all I have is a standing drill press.

Not sure u need a press for this. I didn't but I do know some barrels need drill lathed w sandpaper to fit. Smaller diameters are more difficult to build out to match. I'm messing with getting a carbon sleeve to build one out. Hard to work in oring slots into a 1mm sleeve so the idea is to install in sections, leaving the oring gaps between smaller pieces of sleeve. From my mental calculations (assumptions) this will work and fit well.

 

[WOW]

Original .25 on top. Modified Crosman .22 on bottom. The quality orings hold pressure well even when overextended like this, but it's usually hard to install it without slicing up an oring or two, oiling and trying again w a new ring. Touchy install. The bad quality orings just over flex and break instantly. Notice the transfer port is smaller than stock, its my drillbit size not the crosman size, and it's helping me limit my fps to sub-700. Promise, use a bigger hole and the fps will skyrocket. Also if your bolt seals perfectly you'll also get a major boost. Mine is loose by design in the .22 but the 25 barrel would fit way better with a stock .25 bolt.

 

[daddypaddy]

Thanks man.
If I bought a 2,500$ gun it would be in pieces within a week anyways lol

lol i im the same

 

[WOW]

Upgrade:
The crosman barrels may be a tad over 11mm, sanding down let me fit a 15mmOD 11mmID carbon fiber sleeve. This is to deal with the barrel whip of the longer unsupported, as is the tuner.

Had to get a 15mm bit to try drilling the Jet shroud for a recess, but there is zero clearance, and the metal thread set into the Jet tip for moderators just bent outward, did not want to cut and drill out. Maybe a soldering iron removal of that piece is better.

The moderator is a Frankenstein monster I made by super gluing a Buick Rail supressor which broke at the base to a printed harmonic tuner design. For a junk piece, it works well enough. It's not a perfect glue interface, probably off by 2 degrees but I'm hoping it's ok being that's it's a .25 supressor and I'm shooting .22. I can always cut it, resand and reset it and have pretty much convinced myself to do so.