Vortex Gas Piston...Consistency??

[Airgun.Sniper]

 Is there consistency in this piston...I know Hatsan doesn't lie when it come to fps. But wanted to make sure before I bought

 Thanks

[Flatcar1]

Mine had 15 FPS spread in 5 shots, new out of the box. Now I have about 300 rounds through it and I can feel and hear a smoother shot cycle. I will be running it through the chrony tomorrow and I will see if it really has gotten more consistent and faster. It was shooting .25 cal Polymags at 600 when new.

[Airgun.Sniper]

Mine had 15 FPS spread in 5 shots, new out of the box. Now I have about 300 rounds through it and I can feel and hear a smoother shot cycle. I will be running it through the chrony tomorrow and I will see if it really has gotten more consistent and faster. It was shooting .25 cal Polymags at 600 when new.

 So the FPS is also similiar to the spring airguns???

[Flatcar1]

From what I read on the Hatsan gas piston, it is a little slower but smoother and less hold sensitive. Mine is very hold sensitive and is shooting a 28.7 dome at 560.

[SpringerForever]

Received my remanufactured Vortex spring powered Hatsan Mod 125 Sniper .25 cal 9/25/13 from HatsanUSA. And chronied it the same day. Very happy with the rifle overall & the accuracy/consistency!

Shot it with open sights BRed at 25 yards & altho my eyesight & the sights are not the greatest still managed some pretty consistent groups once I adjusted the sights.

Shot 4 10-shot strings using JSB Exact King 25.39gr pellets & the spread for the 1st string was ~19 FPS & the remaining 3 ~9 FPS. The 1st string probably had some dieseling because it had a high of 724.6 FPS compared to ~705-715 for succeeding shots. The pellets fit very, very tight & I discovered by accident that not inserting them flush with the breech dropped the FPS to ~640. And also by accident, over inserting by ~1/8" dropped the FPS to ~634. I also have a nitro spring powered Hatsan Mod 125 Sniper .25 cal & the same pellets fit very loose. So loose that it's possible to actually flip them out of the breech if the barrel isn't closed properly. That probably explains why it's shooting so 'slow' in comparison. It shoots from the 660's to the 680's depending on conditions. And that's even after a lube tune, minor deburring/polishing & a new JM/ARH seal.

My nitro spring powered Hatsan Mod 125 Sniper shoots 25-26 FPE compared to 28+ FPE for my new to me remanufactured Vortex spring powered Hatsan Mod 125 Sniper. The Vortex version would probably achieve 30+ FPE with another (inaccurate) pellet but I'm not going to bother wasting my time. I've owned 5 Hatsan super magnums & currently still have 3 & at this point know what pellets consistently work best.

[ray in wi]

So there Springman..As you have both....  if you were forced to give up the vortex or the spring powered gun...which one would go?? From the overall shooting experience stand point which is your favored power plant in this model?

[JR]

I have the Vortex 125 in 22 cal and the last time I shot it was 960'ish with 14.3gr. spread was 17 fps if I remember right, I do remember the spread was in the "teens" every bit as fast as the spring model. I would like to try/get a tuned spring model, heard they can actually be smoother, don't know for sure just what I read/heard.

[SpringerForever]

I consider Vortex & nitro rams springs. Just a different type.

But to your question.

Long answer.

I've shot almost 700 pellets thru the Vortex spring powered Hatsan Mod 125 Sniper .25 cal since I received it on 9/25/13, almost two weeks ago. And most, ~660, of those pellets were chronied. Not the norm for me but I wanted solid baseline numbers before performing any mods. Plus, I was curious to see if the Vortex spring would weaken at all.

I've only been back into AGing since this past April so take that into consideration when reading the following.

It seems that the Vortex spring is weakening. Either that or something else is going on. Piston seal? The FPEs on the day I received the gun were pretty consistent at 28+ but in yesterday's shooting session the FPE ended at 25.30. It had started off at 27.33 FPE & peaked at 29.23 FPE for one 10 shot string. The 'anomaly' of that one peak might be explained by the sudden increase in temperature. It very briefly got noticeably warmer because the sky cleared. I'm guessing, from my very limited experience, that the piston seal may have 'softened' a bit with the increase in temperature so it was conforming to the chamber better, producing more power. Based on the one Hatsan Mod 125 seal I've replaced & my online research (GTA!) Hatsan piston seals tend to be very hard. There's hardly any flex to them at all. Very noticeable difference when compared side by side with a JM/ARH or PA replacement seal.

The other thing I've noticed over those ~660 chronied pellets is more variability in the ES. I'm sure consistent pellet seating might have something to do with it but I've been quite careful about trying to consistently seat the pellets in the breech, even going so far as using the flat end of a toothbrush handle to seat them flush with the breech. So ... piston seal?

I don't know at this point.

Hopefully it's just the seal.

Which is why I'm currently undecided as to which I'd pick.

Making the choice even more difficult, I've also got a very nice shooting & powerful coil spring powered refurbished Walther Talon Magnum (AKA Hatsan Mod 125) .22 that I bought used this past June that I really like. Unlike the Vortex, it's still producing consistent 28+ FPEs.

I like the Vortex for its potential, but the shot cycle of the nitro is 'softer'. Even with the Vortex's last few 25-26 FPE 10 shot strings the nitro still has a softer shot cycle at 24-26 FPE with the same pellet, JSB Exact King 25.39gr. Granted, the nitro has been lube tuned, deburred & had its seal replaced with a JM/ARH seal but it was still shooting 'softer' before the tune. Don't know how to explain it but the shot cycle on the Vortex is definitely sharper.

Short answer.

In a perfect world I'd have Vortex mod-ability with the nitro shot cycle & WTM consistency. But since it isn't a perfect world I'll very tentatively choose the Vortex. For now.

[Airgun.Sniper]

I consider Vortex & nitro rams springs. Just a different type.

But to your question.

Long answer.

I've shot almost 700 pellets thru the Vortex spring powered Hatsan Mod 125 Sniper .25 cal since I received it on 9/25/13, almost two weeks ago. And most, ~660, of those pellets were chronied. Not the norm for me but I wanted solid baseline numbers before performing any mods. Plus, I was curious to see if the Vortex spring would weaken at all.

I've only been back into AGing since this past April so take that into consideration when reading the following.

It seems that the Vortex spring is weakening. Either that or something else is going on. Piston seal? The FPEs on the day I received the gun were pretty consistent at 28+ but in yesterday's shooting session the FPE ended at 25.30. It had started off at 27.33 FPE & peaked at 29.23 FPE for one 10 shot string. The 'anomaly' of that one peak might be explained by the sudden increase in temperature. It very briefly got noticeably warmer because the sky cleared. I'm guessing, from my very limited experience, that the piston seal may have 'softened' a bit with the increase in temperature so it was conforming to the chamber better, producing more power. Based on the one Hatsan Mod 125 seal I've replaced & my online research (GTA!) Hatsan piston seals tend to be very hard. There's hardly any flex to them at all. Very noticeable difference when compared side by side with a JM/ARH or PA replacement seal.

The other thing I've noticed over those ~660 chronied pellets is more variability in the ES. I'm sure consistent pellet seating might have something to do with it but I've been quite careful about trying to consistently seat the pellets in the breech, even going so far as using the flat end of a toothbrush handle to seat them flush with the breech. So ... piston seal?

I don't know at this point.

Hopefully it's just the seal.

Which is why I'm currently undecided as to which I'd pick.

Making the choice even more difficult, I've also got a very nice shooting & powerful coil spring powered refurbished Walther Talon Magnum (AKA Hatsan Mod 125) .22 that I bought used this past June that I really like. Unlike the Vortex, it's still producing consistent 28+ FPEs.

I like the Vortex for its potential, but the shot cycle of the nitro is 'softer'. Even with the Vortex's last few 25-26 FPE 10 shot strings the nitro still has a softer shot cycle at 24-26 FPE with the same pellet, JSB Exact King 25.39gr. Granted, the nitro has been lube tuned, deburred & had its seal replaced with a JM/ARH seal but it was still shooting 'softer' before the tune. Don't know how to explain it but the shot cycle on the Vortex is definitely sharper.

Short answer.

In a perfect world I'd have Vortex mod-ability with the nitro shot cycle & WTM consistency. But since it isn't a perfect world I'll very tentatively choose the Vortex. For now.

 Thanks for the info

[ray in wi]

Springer
 Great post! Thank you for the details and your honesty.
Regards
Ray