hatsan at44 10 QE POI SHIFT

Forums PCP Airguns hatsan at44 10 QE POI SHIFT

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    r1d2
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    I HAVE A NEW AT44 THAT WON’T STAY ZEROED IN,I CAN ZERO THE GUN IN THE MORING AND SHOT IT IN THE AFTERNOON OR VISE VERSA AND THE POI CHANGES ABOUT 2 INCHES ONE WAY OR THE OTHER. I HAVE TRIED 3 DIFFERENT SCOPES THINKING I HAD SCOPE PROBLEMS BUT IT STILL MOVES ANYONE HAD THIS KIND OF A PROBLEM.I HAVE NO IDEA WHAT IS CAUSING THIS,THE BARRELL AND TANK ARE TIGHT AND I DON’T SEEM TO HAVE ANY AIR LEAKS.ANY HELP WOULD BE APPRECIATED. 

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    FukoChan
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    You dont need all caps my friend. Make sure your scopes are on decently tight onto your rail. Id suggest you take apart your gun and clean the barrel. Anyone have any other suggestions?

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    Bwalton
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    Cleaning barrel, o rings, clipping, loose scope, in correct velocity,

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    r1d2
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    cleaned the barrel today and found the barrel shroud was loose i tightened it.hope to try it tomorrow, to much snow to cold and to windy today

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    GoneShootn
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    I have two AT44 rifles, a .25 long and a .177 short, both standard (not QE) versions, and both have the same problem. With the .177, I can shoot 4 decent 5 shot groups at 29 yards, and then pump the rifle up and, without doing anything else, the next 4 groups would be a total mess. Or, with either rifle, I can shoot a pretty tight group, and then the next group will be tight, too, but in a completely different spot. I hope you find a fix, because I haven’t been able to.

    The stocks on both of my rifles are synthetic, and I think that flexing with the smallest movement or change of hand position is the culprit, but I may be wrong. Also engineering that allows tiny changes of pressure on the stock to cause significant changes in POI. What kind of stock does your rifle have?

    I have spent hundreds of dollars and hundreds of hours screwing around with these rifles, and the only thing I have realized for my efforts so far is a mountain of frustration. Just FYI, I also corresponded with another person on the GTA forum who at one time or other had 3 different AT44s, and all had POI shift issues, whether wood stock or synthetic. So I don’t think this is an uncommon problem, but it’s one that the “reviewers” never mention. Strange, isn’t it?

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    Bwalton
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    po[ shift is something that a person is missing. like D2 sates he had some thing loose, could be an blown o-ring. or scope. some scopes when you adjust them it takes time for them to settle in, fill pressure if its an unregulated rifle can move poi..Have to know what to look for.

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    GoneShootn
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    @bwalton
    You are a total magician with these rifles. You are the “Hatsan whisperer”. They speak to you and tell you how to fix them, and you have the ability to do that. Unfortunately, most of us do not have that talent. The TACT versions may be different, but I think all of the regular synthetic stocks are bad on the AT44s. When you remove the barrel band, and the point of impact immediately goes up 6 inches at 29 yards, there is definitely a problem. And that’s with the second stock. But, even if the stocks were true, they are thin and very flexible. I would try a wood stock, but I am not of a mind to spend $100 or more on what could easily be another dead end.

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    AG72
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    Hi there, i have the wood version, it’s a .22, my gun got much more accurate when i removed the barrel band, try that if you haven’t! And Mr Bwalton is mentioning something else, the scope on a pcp, it take some time to change after you turn the wind and elewation, it’s very easy to drift away with the turning cause the scope doesn’t react imediatle cause there is no recoil,like in a springer where u se the changes after a couple of shots,i use the plastic handle of a screwdriver to gently tap the scope a couple of times, best of luck to you!

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    Lou
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    See if you have baffle strikes on the moderator/shroud…

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    GoneShootn
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    Just a thought:  How is the gun resting overnight? If, for example, you allow it to rest upon a bipod, as I do sometimes, then the bipod is very forward on the stock, giving it high leverage, and it exerts an upward force upon the stock over time. As the rifle sits for a long time, it adjusts to this pressure, forcing the POI up. Then, if you shoot the rifle, say, on a bag rest more toward the middle of the stock, as you shoot it, it gradually adjusts to the new pressure point, and the POI could move down. This is definitely a problem on the standard synthetic stocks, but I do not know about the Tact synthetic stocks or wood stocks. Like I said, just a thought.

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    Lou
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    I have the first gen at 44, sometimes I leave it on the bipod, sometimes I leave it in the bag, sometimes rested against the barrel, sometimes against the scope, it got bumped around during the entire hunting season and on the last day I accidental dropped it from 6 feet high on sharp rocks and when I went home I still took out a matchstick with it at 55 meters without having to adjust zero, so if you have POI shift something is very wrong, I would look at the silencer first and get a chrono to see how it shoots. Also make sure to have a good scope and specially good scope mounts. 

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    NeilClague
    Spectator
    Spectator

    I have had 5 different Hatsans and have not has any problems with any of them, POI shift or anything else, except for one that the gauge leaked on, that was a simple fix. Maybe I am just lucky but so far I have had nothing but exceptional shooters with the Hatsans. One of the first things I ask any customer if they have POI shifts is if they are leaning their guns against something, mine are all laid flat or standing upright in a gun rack. I learned my lesson by leaning my Mrods against the wall, they drove me crazy with their constant POI shifts, it can happen with any shrouded gun unless the shroud and barrel are hard mounted together, good luck with your fix, Neil.

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    GoneShootn
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    “Lou”I have the first gen at 44, sometimes I leave it on the bipod, sometimes I leave it in the bag, sometimes rested against the barrel, sometimes against the scope, it got bumped around during the entire hunting season and on the last day I accidental dropped it from 6 feet high on sharp rocks and when I went home I still took out a matchstick with it at 55 meters without having to adjust zero, so if you have POI shift something is very wrong, I would look at the silencer first and get a chrono to see how it shoots. Also make sure to have a good scope and specially good scope mounts. 
     

    
Yes, something is wrong, but I’m pretty sure the problem is in the limp noodle synthetic stock.

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    peterdulux
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    Couple things, if it’s a steel tube air cylinder, it expands when filled and contracts as it empties.

    Get a appropriate sized drill bit and take the magazine, put the bit through the probe hole and spin it and see if it wobbles. A couple of mine wobbled so bad that they would bind when indexing in the gun. So that would mean that the pellet is not lining up with the bore causing it to clip or even misalign with the bolt probe causing a deformed pellet.

    I heard if you were to move into a wooden stock that things would improve.

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    GoneShootn
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    @lou
    “…when I went home I still took out a matchstick with it at 55 meters without having to adjust zero.”

    Okay…
    What caliber?
    What pellet?
    What velocity?

    Have any groups you could post?

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    GoneShootn
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    Just to show how it goes with these guns, I just got back from a mini-vacation in the mountains. Before I left, I was fooling around with the AT44 .177. From only 1 valve hole open, I went to 3 open and backed off the hammer spring 1.5 turns. The JSB Heavies were obviously still travelling too fast, and the groups were all over the place. I had tried the JSB Monsters several times before with no luck at all and decided to try them again at this tune with the second 10 shots on a 180 bar fill. Those 2 29-yard 5-shot groups were good. If both superimposed, all but one shot would be in a less than 1/4″ hole with that one shot just outside. So progress? Here’s what I posted in my journal along with a photo of the groups:

    “Have we made progress? I guess we’ll see, but history is against.”

    You see, I knew better. Yesterday, when I got home, I couldn’t wait to try again. I accidentally filled to 200 bar, though, instead of 180, and then, with cautious optimism, shot 12 5-shot groups at 29 yards, using the Monsters. Not a single group was worth keeping. Not one. All in the 1/2″ to 5/8′ range or more. Many $150 springers would do that well. If you can’t hit a dime every single time at 25-30 yards with a rifle, then I think it would be unethical to hunt with it.

    I had previously removed the barrel bands on both the .177 and .25 versions, so I guess the next step would be to remove the stocks altogether.

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    Lou
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    “GoneShootn”@lou
    “…when I went home I still took out a matchstick with it at 55 meters without having to adjust zero.”

    Okay…
    What caliber?
    What pellet?
    What velocity?

    Have any groups you could post?

    
.22 Baracuda Match 240 m/s regulated. Mtc Viper Sprtsmatch mounts. I don’t really take pictures of groups, don’t shoot paper with this one much either, I check zero after each hunt that is all, it’s my oldest rifle, I know it and trust it. I had POI shift problems before, but since I have upgraded the scope mounts, zero problems and this gun is used and abused. I never had any major problems, some bad screws and small stuff like that. I never actually cleaned the gun (except barrel) since I got it which is 4 years ago, it has shot tens of thousands of pellets and is still running strong. 

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    NeilClague
    Spectator
    Spectator

    One thing I did find with my Hatsans is they have a sweet spot at 2600psi, if I fill to above that, the accuracy is not there, so I just fill to 2600psi and have no problems. I not sure why the extra psi causes problems, maybe as someone stated, the extra psi causes the air tube to expand enough to effect something?

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