Huben K1 Review And Insight Into Accuracy Problems

[Verve]

I suppose it depends on what one wants out of this rifle.

For me 900-1000fps would be enough to shoot readily available .22 pellets, and ST barrels seem to manage that power and these pellets quite well.

Hopefully some pellet manufacturer willl come to rescue.

 

[Gregor]

I assume that regular .22 airgun pellet would work fine with ST barrel. I will test regular pellets (JSB 16 and 18 grain) with my barrel (.22LR) to see if they shoot well and let you know. I do not know why they did not shoot well at all with stock barrel, maybe because it is not choked...

 

[Verve]

That should be a good comparison. As you probably know already, 1/2 inch groups at 50y are common with .22 (shooting jsb 18gr at appx 900fps) and .25 (shooting jsb 25gr at 850+) ST barrels.

Also trying to understand the reasons for selecting .22 cal and the type of barrel by the manufacturer if there's not at least 1-2 specific ammo it's recommended to shoot very accurate to a specific distance. Or its left to the buyers to figure out for themselves.

 

[Nutcracker]

As to the FX ST barrel, I have a 24" one on my Royale 400 & I am shooting 1000 fps with 18.1 JSB less than 1/2 groups easy all day long @ 50 yards. Never tired to get over 1000 fps.

 

[peole]

Daystate .22 has similar energy as Huben and uses exactly same chocked LW barrel part #. Looking at youtube it is sub moa at 50 and less than 2 moa at 100 yards.

One thing that I noticed about Huben shroud/silencer - it has no expansion chamber. Here are guts

baffles and spacers:

Looking at this - baffles are not exactly positioned in shroud - giving not linear air blow by.

Here's JSB Beast inside baffle - enough clearance to not hit:

Fact that expansion chamber is missing suggests that air blows right at widened end of pellet at pretty much full pressure.
Hitting badminton shuttlecock at skirt is usually pretty misbalancing event.

 

[wlbryce]

Peole, this is interesting! I never took the shroud apart. I will shoot the original barrel this weekend to see how it acts without the baffles. I do know from other guns both air and powder burners that a silencer does mess with POI and can produce fliers. I should have looked at this to rule it out over the barrel. My Huben differs from the one you show, the holes in the shroud are different and my barrel is not threaded, it just slides into the spacer before the first baffle.

 

[Gregor]

I have tried huben without t shroud and the results were the same. The POI does change a bit but the pellets are still not stable an therefore not accurate. The shroud does effect POI on the new .22LR barrel but the pellets ares still sable and the gun is still accurate.

Huben has different shroud than most airguns, it has baffles that fill the shroud and holes on the shroud to evenly diffuses the pressure. This makes it very effective in reducing the sound. Most of the air goes out of the holes around the shroud. this shroud also slightly reduces the recoil if you compare it without the shroud.

 

[ksfastman]

I haven't shot for grouping without the shroud, but I think it performs very well at Umm audible/sound reduction.It's got quite a bark/report without it.

 

[ksfastman]

Accuracy is a very subjective topic, what the heck would you call a set of standards for gauging accuracy? With center fire rifles we've used machine rests, hydraulic trigger releases/actuators, hand loaded ammo, an indoor range and you'll get very different groups taking the gun out of the "Rig" and having a different person set it back up.

 

[ksfastman]

I'm kind of disappointed that I've let myself get involved in this thread. I really enjoy my K1 and that's all that matters.

 

[peole]

"Accuracy is a very subjective topic". Accuracy It is very well defined and defacto standard is 1 MOA at 100yards for 3 shots. Pretty much every decent centerfire rifle (priced in $ range of decent PCPs) can hold 1 MOA at 100-200 yards. Good ones hold 1 MOA to 400-600 yards.

for air rifles i'd say 2 MOA at 50 yards (1in groups) and 3 MOA (3in groups) at 100 yards is what best ones can do.

 

[StormSunny]

Let's assume 20mm at 50 meters. If you cannot achieve that in perfect conditions with the right pellet - something is simply wrong.

To be honest the difference in the twist rate: 1:17" and 1:16" is really small. E.g. the barrels mounted in EDguns have 1:16" twist rate.

I think the problem was with the quality of the barrel. If you grab a quality 1:17" you may discover it shoots pretty same to 1:16".

 

[Gregor]

Minor correction, the stock airgun barrel is 1:17.7, so almost 1:18... A agree with you, the difference is small. I did not expect resoults thi good. The reason I choose this barrel is simply because if you think about it, this airgun is more similar to .22LR than any other airgun. The fact that this barrels stabilizes the pellet only at higher velocity only confirms this theory. 
BTW, the stock barrel it lothar wlather as well and the crown looks decent on it.
If in fact EDgun has 1:16" barrel from LW, then they must be a custom made barrels because LW only offers 1:17.7" as stock. I was in contact with LW several times, because I wanted an airgun barrel with 1:12" twist at first but settled with .22LR (1:16") because the custom barrel would be much too expensive.

 

[Gregor]

I forgot to mention: keep in mind that all my testing is with longer pellets or bullets (JSB beast,...). 1:17.7" twist perfectly fine for regular pellets.

 

[Templar]

12mm in diameter barrel is too thin for the gun shooting at 22lr energy. It would be nice to see the Chinese make this thing right from the start.

It needs a larger receiver box, a wider in diameter barrel - 18mm minimum with faster twist rate to shoot slugs. Also a removable magazine like an inline Steyr mag for example is very cheap to produce. A pressure gauge in front of the air cylinder so people could tell the amount of air left in front of the regulator in the air tube. Pressure gauge needs to be threaded in also, and moved to the right side, away from the shooters cheek. These are just the minimum revisions they need to do. Also there should be no cast made aluminum parts in today's pcp's.

I think that is the main reason why we don't see that many of these guns being sold. People are worried getting involved with these. Price should be much lower also around 650-700$ is all they will sell for given the fact where and how they are made.

 

[Templar]

ksfastman, these types of bullpup designs where the barrel is connected to the air cylinder and I am talking ckicket and the like guns can never be super, super accurate paper guns. The barrel needs to be free floated for that. As pressure changes in the air cylinder it is pulling on the barrel causing slight random POI shifts. Cricket owners complain about this often. And even though the manufacturer has a special way of tightening the action clamp screws the problem still exists.

Hubens are cool guns but pricing vs build quality is just unreasonable. $100 more buys one an FX Bobcat, which is technically the best designed pcp today if we are talking value for the money here and user safety - which this valving system set up these Hubens use has none. What happens if the trigger sear holding one of the valves closed fails? Massive air dump? The possibility of this is real.

 

[peole]

Gregor, leaving twist rate discussion aside.

You're probably one of few who has original LW barrel out - can you please take close look at entrance part of barrel and take few pics, if you can. 

There are interesting points about revolver specific accuracy issues

here:

https://en.m.wikipedia.org/wiki/Accurizing

(scroll to 'revolver specific issues' section there) 

I want to know IF forcing cone is machined in to LW barrel.

Thanks!

 

[Gregor]

Hi. I will make some pictures when I get home. I have made a forcing cone on my custom barrel (with the conical beginning of 5.7 mm reamer). The original barrel seems to have a less aggressive cone though... I have fired a few pellets into water and they do not appear to be damaged... 

 

[peole]

Thanks!

Also, try to feel with piece of wire IF there's machined groove for sealing ring which is common for bolt action air rifles.

From your take it apart video. How pellet is delivered from rotary mag in to barrel - is there mechanical part or air just blows pellet in to barrel?

 

[Gregor]

Sorry for the delay, here are the pictures...

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The cone is relatively mile... 

Yes, air blows the pellet in the barrel. Huben shoots form the magazine...