Huben GK1 “longey”

[weevil]

Another goofy experiment. Added a K1 plenum and Huma reg to the GK1, to make the .22 “longey” GK1 carbine or GK1/K1 hybrid, if you prefer. Awaiting the arrival of the moderator, which will extend 2” beyond the tube. Shooting AVS 22 grain slugs at 925 with ES of 8 at 150bar reg pressure. Waiting on the mod to fully evaluate accuracy.

Will likely remove the CF wrap from the tube for a more consistent look if happy with the end result. Action end fill port is disabled and gauge reads reg pressure.

 

[JaceSpace1369]

Another goofy experiment. Added a K1 plenum and Huma reg to the GK1, to make the .22 “longey” GK1 carbine or GK1/K1 hybrid, if you prefer. Awaiting the arrival of the moderator, which will extend 2” beyond the tube. Shooting AVS 22 grain slugs at 925 with ES of 8 at 150bar reg pressure. Waiting on the mod to fully evaluate accuracy.

View attachment 524857

Will likely remove the CF wrap from the tube for a more consistent look if happy with the end result. Action end fill port is disabled and gauge reads reg pressure.

My man you are like an evil mastermind, I love your posts, keep it up!

 

[Sergey1972]

Another goofy experiment. Added a K1 plenum and Huma reg to the GK1, to make the .22 “longey” GK1 carbine or GK1/K1 hybrid, if you prefer. Awaiting the arrival of the moderator, which will extend 2” beyond the tube. Shooting AVS 22 grain slugs at 925 with ES of 8 at 150bar reg pressure. Waiting on the mod to fully evaluate accuracy.

View attachment 524857

Will likely remove the CF wrap from the tube for a more consistent look if happy with the end result. Action end fill port is disabled and gauge reads reg pressure.

Love it. Did the same thing. Made a 12 or 13 inch barrel 1/2-20 threaded barrel. Just haven't had time to put it back together and make a shroud. Just received k1 sight rail.

 

[weevil]

Love it. Did the same thing. Made a 12 or 13 inch barrel 1/2-20 threaded barrel. Just haven't had time to put it back together and make a shroud. Just received k1 sight rail.

I thought about using the sight rail but I think it’ll be fun to try an unregulated K1 with some heavy slugs.

 

[AJ_Roberts]

Interesting! I’m surprised no one has bought out a bottle conversion for the GK1 yet, a 220cc bottle would work nicely

 

[Airgun-hobbyist]

Nice experiment. I like the addition of the plenum and regulator. Would you put on a slightly longer barrel to improve power and gain shot count? I ask because since I bought my GK1 I've been talking with folks about producing a 12" barrel and shroud extension kit to make a mini carbine version. That was a year or so ago and this longer, higher power version seems like it would be nearly as popular as the shorty.

 

[sb327]

Interesting! I’m surprised no one has bought out a bottle conversion for the GK1 yet, a 220cc bottle would work nicely

It is probably due to the fact the Huben doesn’t have a solid mounting system to the tank/tube. It has a system that relies on pressure to make it semi rigid. This works in the k1 with support being added by the stock. The gk1 doesn’t need much support due to having a short tube.

Some may be fine with this but in my opinion, the design doesn’t lend itself well to integrating a large reservoir without some form of added support.

Dave

 

[JDGriz]

My neck begins to hurt just looking at this picture (because of the eye relief).

 

[weevil]

Fair point JD, but I’m not touching that scope until I’m sure that it’s going to stay this way for a while.

 

[weevil]

Update. Well as usual it’s 2 steps forward and 2 back.

First, it leaked since I last posted. The yellowish oring between the original fill port block and tube was crumbling, so I refreshed all tube Orings.

Finding a good mod for this unit is not easy due to the airtube. Fortunately a good friend helped me to get one with a cutout to sit freely on the air tube, clocked with a shim.

Upon reassembly, the 3DP stock was found to be impeding the trigger linkage, preventing trigger reset, so I sanded that region of the stock to free it up. Be aware, if you should get the same stock.

Finally, as far as I can tell, it is shooting very accurately. However, wind was not favorable even with slugs for serious testing. 20mph and swirling. The ES from 10 shots was 3fps.

If it proves to be accurate, consistent and robust, it will get the thermal. The rancher who manages the land where I ski will appreciate some help with a certain problem.

 

[weevil]

I have to add that I do not like the look of that sliver of plastic behind the top of the grip. It seems to be robust enough but looks whacky.

 

[subscriber]

Looks good, weevil!

 

[weevil]

As Dave pointed out, the pressure in the tube is the only thing maintaining its rigidity, so I worry about it pressing the mod when the tube is placed on a bag. Hopefully the gap is sufficient. Another option is to add a band around the end of the shroud and the tube, maybe with a very thin spacer to prevent collision between the tube and mod. Typically, I don’t like joining a barrel/shroud to an airtube, but perhaps it’s the lesser evil here. Anyway, this is my major worry, relating to the functionality of the “longey”. It’s no use to me if it needs to be treated with kid gloves to maintain a consistent POI.

 

[JungleShooter]

Interesting! I’m surprised no one has bought out a bottle conversion for the GK1 yet, a 220cc bottle would work nicely

Looking at all the mods available for the GK1 — THAT mod might get me to spring more money on this expensive but amazing gun.

I already have the 220cc bottle.
Take my money for a Z bottle-connector!

Matthias