Hatsan Jet

[JPSAXNC]

I finished up my .22 cal. barrel and probe, I made the new barrel 1.375" longer than stock. Here's a string with 14.3 cphp's 582 584 593 578 585 584 586 584 592 594 594 592 595 596 599 601 599 607 595 598 597 602 593 590 591 588 587. 27 shots AV 592 11.1 fpe.

[JPSAXNC]

I made a .25 cal. barrel and probe for my Jet One. The barrel is 1.5" longer than stock, here's a string with 19.9 grain Diana domes.  22 shots  539 546 549 550 552 556 557 557 556 555 560 560 557 559 557 556 556 557 559 556 554 548.

[naptemp]

I made a .25 cal. barrel and probe for my Jet One. The barrel is 1.5" longer than stock, here's a string with 19.9 grain Diana domes.  22 shots  539 546 549 550 552 556 557 557 556 555 560 560 557 559 557 556 556 557 559 556 554 548.

How did you make the barrels and the probes?

[JPSAXNC]

I decided to keep my jet pistol in .22 cal. Here's two strings with 14.3 cphp's  #1  583 593 593 591 594 596 598 603 597 598 603 602 605 601 598 609 603 607 604 606 602 610 597 600 602 588. #2  605 604 616 619 615 619 621 623 621 631 622 618 621 620 622 617 617 629 616 625 617 609 . Shot to shot consistency is lacking. It's better at lower velocities.

[JPSAXNC]

PS. The diameter of the metering lip/sail on the second string is .002 smaller.

[JPSAXNC]

I miss spoke when I said the shot to shot consistency was better at lower velocities. I'm pretty sure the reason those two strings are more choppy is due to turbulence. Here's a string in .25 cal. that's faster with a heavier pellet, and with very good shot to shot consistency. Enough shots for two magazines with a 17 grain pellet.  611 604 613 611 609 607 609 610 614 611 614 612.  The metering ring diameter on string #2 above is .333, the metering ring diameter on this string is .316 giving a longer dwell time, so the poppet was in a different area of the valve where there was less turbulence, and better flow.

[naptemp]

Unfortunately out if the box a Hatsan Jet shot string looks like a flat tire.
If it shot like yours I would buy it.

To get it to shoot like that you used your skills, tools and time.

I am not going to do that when I can buy an Umarex Notos which shoots great out of the box.

[JPSAXNC]

Hi John, I didn't have any interest in buying the Jet. I saw some utube videos, and then looked up the exploded view of the gun. I could see that the valve internals might be improved on and I figured that I could get a good string out of it. And I wanted to see how much energy I could get out of 40 cc's of air. That's what I like to do, that's my airgun thing. I think the engineering alone was worth the asking price and that the gun is a bonus.

[JPSAXNC]

Another choppy string, but there's 34 shots,  .22 cal. 14.3 grain cphp's  554 554558 555 563 560 567 563 566 569 570 568 570 573 568 565 575 577 573 572 575 575 579 572 576 575 576 575 577 575 575 571 570 564.  I think the heavy valve return spring I'm using is to heavy.

[JPSAXNC]

The choppy strings, ( a fast shot followed by a slower shot followed by a faster shot), were caused by turbulence. The turbulence was caused by my leaving sharp corners with a little burr on the metering lip on the poppet. I usually round the corners off slightly, but I wanted to see what sharp corners would do. Here's a string after I rounded off the corners slightly, this is the only change I made from the 34 shot string above. 606 611 607 613 614 614 618 623 619 621 622 625 626 625 625 625 627 624 623 618 .

[Back_Roads]

 

[JPSAXNC]

28 shots with .22 cal. 14.3 grain cphp's   589 583 576 585 583 587 594 604 598 599 596 604 612 603 605 609 604 611 607 609 609 610 604 611 601 596 595 589. This is probably the best string I can get for shot count, shot to shot consistency, and velocity. There's always tradeoffs. Trying to get more of one thing will take away from something else.

[Rob M]

I made a .25 cal. barrel and probe for my Jet One. The barrel is 1.5" longer than stock, here's a string with 19.9 grain Diana domes.  22 shots  539 546 549 550 552 556 557 557 556 555 560 560 557 559 557 556 556 557 559 556 554 548.

How did you make the barrels and the probes?

hes a machinist

[JPSAXNC]

Another string, in .22  31 shots 14.3 cphp's   594 590 592 596 592 589 585 589 586 593 594 596 606 600 599 605 601 606 603 606 607 600 613 607 602 603 609 606 598 592 590.  I  installed an o-ring in the back of the valve to seal the valve stem, I think it made a difference and saved a little air. This string looks like it picked up a few shots

[JPSAXNC]

Trying for a 12 fpe. string, .22 14.3 cphp's   623 616 612 610 622 623 623 621 625 623 628 635 631 626 623 640 627 628 627 626.  20 shots  AV 624  FPE 12.3   The strings I shoot have a typical bell curve, but the odd thing is the second and third shot are almost always slower than the first shot, then the velocity picks up, I don't understand why?

[EdinGa]

I just got a Jet 1 in .25. Man I love this thing! All I'm looking for is 12 fpe and I've got some big plans for it.

[ray1377]

You fellows say the Jet is more pistol like than the Notos, how does it feel weight wise? It looks to be mostly plastic so I'm guessing on the lighter side?
Am looking to get a small inexpensive pcp pistol to get my granddaughter into shooting airguns. The lighter the pistol the better in her case.
Thx
Ray

[EdinGa]

You fellows say the Jet is more pistol like than the Notos, how does it feel weight wise? It looks to be mostly plastic so I'm guessing on the lighter side?
Am looking to get a small inexpensive pcp pistol to get my granddaughter into shooting airguns. The lighter the pistol the better in her case.
Thx
Ray

Mine weighs a touch over 3lbs with the red dot I have on it. It'll probably still come in under 5 when I'm done with it. It's a solid feeling little carbine even with all plastic.

[JPSAXNC]

The Jet in .25 can make 12FPE. in stock form. All you have to do is slow down the shot cycle enough to get a consistent string. Using a much stiffer valve return spring will help a lot. Also if you can make or find a thin washer (.050 thick with a diameter of .330), and slip that on the poppet stem where the the valve return spring sits, (the return spring will hold it in place) that will get a more consistent string.

[EdinGa]

The Jet in .25 can make 12FPE. in stock form. All you have to do is slow down the shot cycle enough to get a consistent string. Using a much stiffer valve return spring will help a lot. Also if you can make or find a thin washer (.050 thick with a diameter of .330), and slip that on the poppet stem where the the valve return spring sits, (the return spring will hold it in place) that will get a more consistent string.

I'm going to bottle mine. I've got 800, 1100, and 1800 psi bottles to try, but I'm hoping the 800 will get me where I want to be. It's pretty quiet at that pressure and I like the length without a suppressor. Thanks for the tips though. I might be able to use some of them to make it more efficient.


Would you happen to know the thread size of the male foster fitting they used? I know it appears to be 1/8 but it isn't npt.