Hatsan nova question

[Bigdog12]

I just recieved the nova in 22cal the gun does not leak air just sitting there but when

The gun is fired there is a big loss of air coming from between the stock and action

I took the gun out of the stock and started looking what is going on. On the bottom of the gun between the block that holds the bottle and the front mounting screw 

There is a 1/4 hole and when the gun is fired a gush of air comes out of the hole

The valve body is under that hole.

I am not going to open up the gun any further since its brand new

I was just checking if this is normal or what everybody thinks is going on

 

[Rodeo]

No, it should not blow air out that hole. Sounds like a bad o-ring part # 2359. This is one of the o-rings that seal the firing valve in the hammer tube sleeve (the one closest to the firing pin). It is also possible that the firing pin o-ring (part # 2313) could be bad / but this one is not the likely culprit. One other possibility is the transfer port o-rings but again not the most likely cause. My Nova had a bad o-ring # 2359 when I got it and did the same thing. During assembly this o-ring is easily damaged so be careful during reassembly if you decide to replace it yourself. There are two set screws in the side of the hammer tube sleeve that you have to remove to get the bottle/block/firing valve assembly out. Draining the bottle is not necessary to replace o-ring # 2359. Hatsan USA website has parts diagrams.