Diana skyhawk .25

Know the that the magazines are notoriously crappy . You probably will need to get some DARKO mags. The trigger linkage is flimsy and needs work as does the trigger parts. rough not smooth. If you are lucky and get a good one then YAY if not send it back fast and ask for a new one. The .25 barrels seem to have had more problems in the P15 and Diana says they are using the cream of the crop snow peak barrels. The .22 and .177 barrels seem to be ok. OK does not mean great just ok.. I have had both and these are real time experiences. Nick
 
Molder

I purchased a Skyhawk .25 about 3 months ago. I had read various reviews and forum threads so I knew that I was going to have to spend money and effort getting it right. The reason I purchased the Skyhawk was the adjustable butt stock and weight. I have had issues getting my various PCPs to fit me so that when I shoulder them I could get consistent scope/eye placement and feel comfortable. I got the Skyhawk with Sport Match adjustable rings to fit me the way I want a rifle to fit (best fitting rifle I own). Now to the initial performance - with JSB Exact King .25 - 25.39gr got an average of 801 fps with an extreme spread of 22 fps. Turned down hammer spring half a turn and got 790 fps with an extreme spread of 10 fps. Initial issues included trouble with shroud/baffles (seems to be a common issue) and a barrel in need of crown and leade rework (never seen a crown look as bad as the Skyhawks). Had a local gunsmith rework the crown for me and I put the rifle back together. My intent was to do some accuracy testing when the pin that holds the cocking lever to the cocking mechanism fell out (another common issue with the Skyhawk). I am awaiting a replacement pin. Even with all the issues I will continue to try to get the Skyhawk right because I really like the fit and weight. With all this said I would recommend the Raptor Mini because it will be right out of the box and have a higher fps ceiling out of the box. Also the folks at JSAR are a class act and will take care of any issues with their rifles (but I doubt you would have any issues with the Raptor Mini).
 
I checked a lot of P15 at 4.5 but most at 5.5

All of them had good barrels, but i cant say the same for 6.35

The broblem with cal 6.35 is that the block is made for smaller calipers and because of that the low pressure volume is not enough for high power, the solution for this is a huma reg with the bigger plenum or an extra plenum for the OEM reg, you can get over 45 fpe with that
 
I bought one of the first 22 Skyhawks, waited a month or two for P.A to get it in.
I knew of the p-15 QC problems and planned on going to the next level if need be because of that lovely stock.

The barrel had a tight spot just ahead of the chamber, it shot terrible, I lapped it and it improved a bit but not enough. Power was at 28 FPE. The shroud was threaded crooked at both ends so Donnyfl goods made it clip badly. But any device would have that is why you see them sporting Koi’s directly on the barrel.

I sent it to JSAR had a 20 inch lw poly choked barrel put on it and a Huma regulator. It was still 28 to 30 FPE at that point.



I then sent it to Lee 545, I had him make a new shroud proportional to the 20 inch barrel, instal his 25 cal plenum, and correct other short comings. 
I polished the trigger and adjusted it, bought aDarko magazine.

It now is the nicest looking, most accurate and if I turn it up, it does 895 FPS plus/46 FPE with 25.39 .22 caliber JSB’s. The trigger is crisp, under a pound no creep and the safety still works.

But there is more. Just because I have a large amount of air on tap does not mean I have to use it, so with the hammer spring adjustment flush, it is back down ar 28 FPE, turn the adjuster in a few turns and it is at 46 FPE!

side note, when Lee installed the plenum, I had at that time turned the regulator up to 145 bar,

Lee545 does excellent work.I have over what a Veteran would cost, and am glad I did it.
1575384484_1451818035de675a48b0254.83672517_00EA9BC1-AB15-4F9C-A761-CFB27DCA3A9F.jpeg




Roachcreek




 
In my opinion, the Skyhawk/P15 action is more suited to .177 or .22 calibers. It might be a little anemic for .25 caliber. I have a .177 Skyhawk that I used for FT most of last year, but I now have a JSAR .22 Raptor on order for long-range/high-power shooting.

The Skyhawk does have a few issues. Mine shot just OK from the factory. The factory barrel had some issues so I re-barreled mine with a LW poly barrel and it now shoots very good/great.

The factory Skyhawk magazines never fed smoothly, so I have only used the Skyhawk with the single shot tray. I plan on sticking with the Skyhawk for FT - I do like it. When I shot FT with my Marauder rifle, I always used magazines. Same for my Marauder pistol.

I was hoping that Diana/SPA would address the magazine issue since it has been a known issue for a long time. I won't buy any more of their magazines until they fix them, but I decided this morning to at least fix the two that I had. The axle hole in the center array piece of the magazine is slightly off center, so that would be a likely place to make an improvement, but it would not solve a more fundamental problem - off-center tolerance stack-up. The solution is simple but it does require a new housing or modification to the housing. The torsion spring holds the pellet against the side of the stop, not at the center of the stop. Apparently, the designer did not take that into account when designing the Skyhawk magazines. I made a new housing with a 2 degree rotation of the stop to take up the tolerance. It now feeds very smoothly.

www.scotthull.us/photos/3D%20print/Skyhawk-magazine-03.jpg

www.scotthull.us/photos/3D%20print/Skyhawk-magazine-00.jpg

www.scotthull.us/photos/3D%20print/Skyhawk-magazine-01.jpg

www.scotthull.us/photos/3D%20print/Skyhawk-magazine-02.jpg
 
I just finished testing my high and low hammer spring adjustments effect on velocity on my 22 Skyhawk.

25.39 22 caliber JSB

Spring flush with receiver = 720 FPS

Spring turned in 4 turns. = 900 FPS



I did not test the highest velocity of Crosman HP 14.3 as they are going too fast for my interest, however the flush, or lowest position yielded 880 FPS.

Now remember this is with a Huma Regulator set at 145 Bar and Lee545’s plenum extension.

I personally would call that flexibility.

My JSAR barrel is 20 inches, a LW poly choked, custom fitted, the length requested by me per phone call with Matt when he reached that stage. I believe the drop in barrels are the same length as the oem barrel, but I sure could be wrong.

Roachcreek
 
In my opinion, the Skyhawk/P15 action is more suited to .177 or .22 calibers. It might be a little anemic for .25 caliber. I have a .177 Skyhawk that I used for FT most of last year, but I now have a JSAR .22 Raptor on order for long-range/high-power shooting.

The Skyhawk does have a few issues. Mine shot just OK from the factory. The factory barrel had some issues so I re-barreled mine with a LW poly barrel and it now shoots very good/great.

The factory Skyhawk magazines never fed smoothly, so I have only used the Skyhawk with the single shot tray. I plan on sticking with the Skyhawk for FT - I do like it. When I shot FT with my Marauder rifle, I always used magazines. Same for my Marauder pistol.

I was hoping that Diana/SPA would address the magazine issue since it has been a known issue for a long time. I won't buy any more of their magazines until they fix them, but I decided this morning to at least fix the two that I had. The axle hole in the center array piece of the magazine is slightly off center, so that would be a likely place to make an improvement, but it would not solve a more fundamental problem - off-center tolerance stack-up. The solution is simple but it does require a new housing or modification to the housing. The torsion spring holds the pellet against the side of the stop, not at the center of the stop. Apparently, the designer did not take that into account when designing the Skyhawk magazines. I made a new housing with a 2 degree rotation of the stop to take up the tolerance. It now feeds very smoothly.

www.scotthull.us/photos/3D%20print/Skyhawk-magazine-03.jpg

www.scotthull.us/photos/3D%20print/Skyhawk-magazine-00.jpg

www.scotthull.us/photos/3D%20print/Skyhawk-magazine-01.jpg

www.scotthull.us/photos/3D%20print/Skyhawk-magazine-02.jpg

Really nice work. Must have taken some time to get all the measurements and design the 3D math. What material did you print it out of? I'm a bit concerned using PLA or even PETG because of how it softens in heat...which can happen if you leave the gun in the back of a car.

The Umarex Gauntlet has a similar issue with it's pellet door. It isn't quite as bad on the pellets because of the larger diameter lead in the breech. It causes more of a problem with the probe o-rings which scrape on the misaligned holes and shear off...causing blowby and allowing the bolt handle to flop around.