Leaking piston seal Hatsan 95

[sr500]

Hi guys. I have a brand new Mod 95. Maybe 30 pellets. If i have the gun cocked with no pellets in it, and blow throu the barrel, i can hear air leaking somewhere in the tube.When the gun is not cocked, there is no leak. What do you think, is it a bad seal from the factory? Or is it some slot in the tube, that the air leak throu?.I did try to blow in the barrel on my Mod 125, but there was no leak. Tommy.

[thekid]

I can tell you though, that if the piston ever let go when the barrel is at your mouth... you might not be to worried about the gun any more...cause you will be too busy looking for your teeth.

... WHAT YOU ARE DOING IS NOT SAFE.
 
Edit

To answer your question:  The air chamber only draws in enough air to fill the chamber when the the gun is cocked and the seal on the piston acts like a vacuum.

When you blow into the rifle your are pushing more air in,, and that is the air sound you are hearing.... the air inside is not pressurized until the pellet is in the bore and the barrel closed while the piston is pushing forward compressing and super heating the air up to something like 3000psi.
Rob

[Pete]

AS you describe it....

Heres what could lightly Be happening if it leaks
in the uncock postion but not the cock postion...
in the uncocked postion the seal is pushed against the
end of the chamber by the spring.. that maybe distorting the seal
so it leaks in that postion...

And as stated... putting a cocked gun in yer mouth...
The word "idiot" springs to mined

[sr500]

Thanks for telling me, that i am a idiot.Maybe not the best way to test, but give me another way. happy to lived so long as 53 years. Tommy.

[thekid]

You need a chrony to see if it is leaking... This is done with the different readings from pellet speeds... to much of a difference in the velocities using 10 shot strings with each pellet. indicates a possible bad seal.

 I would change the seal and do a tune on it, making sure of no leaks.
Rob

[sr500]

I think you missunderstand me guys. It was when cocked it leaks, not uncocked. I have shot it in chrono, and it shoots about 650 Fps with 5 coils cut. Tommy.

[thekid]

I understood you perfectly.... Just don't understand why you would risk injury to test for leaks.

most likely undersized seal.. or cuts in seal...or breach seal leaking

Change the seal..but do a deburr and tune first so you do not wreck the new seal.

These are low cost guns... meaning mass produced with the seal just slapped into them with the piston. They are not deburred and most times it is just "good enough" then shipped.

But please do not do what you were doing before... if in doubt put the gun to a glass dish or cup, cock it and without a pellet in it, pull the trigger and see what happens. There will be a lot more frontal movement from the piston slamming home against the receiver.

Good luck and PLAY SAFE.
Rob