Huben GK1 leaks to 100bar after being shot for first time in a week.

[elittle1234]

So after I leave this shorty sitting for about a week, the first time i shoot it i notice a big puff of what looks like gas or moisture being blown out the barrel. It's also louder than normal.

The gun was at 310bar, I shot it once, it did that weird puff of gas thing, then drained to 100bar in about 1 hour.

I noticed the same thing happen in my other gk1. If it sits for a week or longer the first shot is really weird, with a visible puff of something looking like gas and it's louder than normal.

After that first shot it goes back to normal in both guns. I fill them back up, no leak and they shoot fine.

Is this normal? It seems like maybe the valve is getting stuck open or something? Maybe because it's sitting so long and I have the power cranked up it causes the valve to not close all the way on the first shot? Just curious if anybody else has had this happen.

 

[Ezana4CE]

So after I leave this shorty sitting for about a week, the first time i shoot it i notice a big puff of what looks like gas or moisture being blown out the barrel. It's also louder than normal.

The gun was at 310bar, I shot it once, it did that weird puff of gas thing, then drained to 100bar in about 1 hour.

I noticed the same thing happen in my other gk1. If it sits for a week or longer the first shot is really weird, with a visible puff of something looking like gas and it's louder than normal.

After that first shot it goes back to normal in both guns. I fill them back up, no leak and they shoot fine.

Is this normal? It seems like maybe the valve is getting stuck open or something? Maybe because it's sitting so long and I have the power cranked up it causes the valve to not close all the way on the first shot? Just curious if anybody else has had this happen.

No this is not normal after one shot from a 310 bar fill. Reading this I was thinking it’s a valve issue as well. I’m interested in what you identify as the problem. How far is your power adjustment screw cranked up? What sort of velocity are you getting at your power current setting?

 

[elittle1234]

No this is not normal after one shot from a 310 bar fill. Reading this I was thinking it’s a valve issue as well. I’m interested in what you identify as the problem. How far is your power adjustment screw cranked up? What sort of velocity are you getting at your power current setting?

Screw was at 2 turns, maybe a tiny bit more. I was getting in the mid/high 800s for fps. It's still holding air today. Never leaked again after I refilled it. With 40gr slugs I was making about 45fpe. The shorty i haven't chronod after I put the new trigger on, I think it was about 750 fps last I checked.