Vortex Sniper .25 issue

[Lankylegs]

I tried searching for an answer to this but either didn't query it correctly or missed it altogether so please forgive me if it's been addessed already.  I bought the Hatsan Sniper with the Vortex piston in .25 in June of 2018. I honestly haven't shot it much. I'm just finishing up my first tin of a 350 count. I took it out the other day and the first shot seemed normal but I noticed that each subsequent shot seemed weaker and weaker and by about the 10th shot all I got was a dull "pa-dump" sound and the pellet remained in the breech. I recessed the pellet, re cocked and fired and it did expel but at a very low velocity. It probably wouldn't have knocked a tin can over at 10 yards. Also the cocking effort is extremely easy. It almost falls on it's own. I suspect either the piston or a seal? I have to be honest in disclosing I'm not well versed at all into what it could be and am hoping someone(s) here can help me 1) Diagnose and 2) point me the right direction on how to fix or where to get parts. I did email Hatsan but have not yet received a reply. Thank you in advance for any and all help/info! Much appreciated!
-Tom

[Leaded]

Sounds like a bad gas ram. Can get a replacement from HatsanUSA. You will need to specify what sniper you have as the 125 and the 150 use different gas rams. You’ll need a spring compressor (or some means to compress the ram about 1/4”) to get the pins in while replacing the gas ram.
As far as cost, mine (type2 for 150) was in the $40s.

Use customer service request on HatsanUSA site to specify your gun and request the parts.

[mikeyb]

Which Vortex Sniper .25, Mod125, Mod85 or one of the 105/155 series under-lever Snipers?

The Vortex air springs will likely be different models.

I have these rifles in both spring (air and coil)  versions. The Vortex air spring versions do shoot nicer right out of the box, but I've lube-tuned the coil spring versions to shoot almost as nice. Haven't had a Vortex leak "yet". I lean towards buying coil spring version whenever possible because I "think" they will last longer. Just my opinion, no hard data.

The correct replacement Vortex air spring direct from Hatsan will be the simplest fix. Hatsan should know which Vortex to ship based on your rifle model, or you could remove the existing Vortex spring to identify its model number and try to order the same replacement.

[Lankylegs]

I have the Sniper 125...I found a guy that will rebuild the gas ram, clean up receiver tube, hone rear receiver area, & burnish the tube, check trigger and a few other things.

He seems very reputable but it's going to run me $145 plus shipping to & fro.

I'm not opposed to paying it if it's going to leave me with a sweet, reliable shooter. Also, replacing it myself as a novice is a little intimidating.

[Lankylegs]

Anyone else have an opinion on this? My comment above outlines what repairs the third party guy will do and for how much. 

I received a reply from Hatsan finally and they quoted $90 to install the new piston, testing and shipping.

Based on what I wrote, do you think the extra $90 is worth it to have the third party guy perform the work?

[Leaded]

Sorry Tom, Ive done all my work myself so I don’t really have any experience with paying for the repairs. Sounds like you’re getting more work done by 3rd party guy so it could be worth it.

[Back_Roads]

 With Hatsan It may get you shooting again, but with a tuner of good rep. you will be shooting as accurately and possibly longer than a factory fix IMO.
 ME I rather do the job myself, but that me LOL.

[dlee]

Hi there, just saw this thread. Wondering if you've tried to refill the piston yourself first? Maybe it just lost air after sitting for awhile? I recently brought out my Model 95 and it had lost piston pressure after sitting in the closet for about 9 months while I shot PCPs. I first degassed the piston completely using the degassing screw on the side. Then just inserted the Hatsan fillprobe and pumped it up to 125 bar. It's held pressure now for 4 days and counting. I believe Airgunner's Edge has a couple of videos showing him filling his 125 Sniper piston if you search on YT. It's worth a try before you spend all that money.

[dlee]

quick update - this evening my hatsan 95 piston had no pressure again. so I take back what I said in the previous post - you definitely can try to just refill your piston, but it may need to be rebuilt (or you may need to buy a replacement). haven't decided whether i'll try rebuilding mine or just buy a new piston for it. anyway, hope you are solving your issue.