Diana 34 spring replaced...this is NOT what I was expecting.

Yep. After all this back and forth and what not, that is what I'm starting to think as well. That spring is way shorter than the Diana OEM spring. I doubled checked the package, it says HO which should be 17 FPE. It has to be wrong. I'll get it all sorted out as quick as I can.

To be sure, after you replace your seal again, put the OEM spring in and check velocity, then put the Vortek spring in and check again. This will remove any other thing you have done to the gun from the equation. Your Vortek spring looks one coil shorter than mine but it's hard to tell. I see 18 coils above the guide on mine and 17 on yours. Also, your OEM spring seems long. What is the measurement on that length? Here's my OEM side by side with Vortek HO spring. I'm on my third Vortek.

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The Vortek spring is in the rifle, so can't measure that right now. But, I just measured the OEM spring from the base of the guide as you did and mine is right at 11.5 inches. So, it appears that my OEM spring is approximately .5 inches longer than the one you have. But, Vortek is far shorter than what your example is showing. This is of course by eyeballing, as I have not actually measured.

I couldn't stand it. I had to go pull the Vortek spring and measure. There is almost 1.75 inch difference between the two. Thats not that big a difference. Now I'm really scratching the old head. 

And yes Seven08. I'm glad I went ahead and tore into it. I've done it three times now and it really is very easy to do. No better teacher than experience.



Thanks fellas 

Seven08

" Did not see your scope on the gun during your chrono testing? "

Yeah. I took it off because I knew I was fixing to tear it down, and my spring jig mounts to the scope rail. It's not broken yet!! Little Hawke is still doing just fine so far.

TR

Hey, TR....while yours is tore down, do me a favor. See if your Vortek spring will slip over the original RWS spring guide. I hate to tear my down for a try if yours is already. Much obliged.

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Well. I just took it apart swapped the springs again and put it back together. But yes, I'll do that for you, because I'm gonna take it back apart again anyway. Just give me a few minutes and I'll have your answer.

But I have an update on my perdicerment. I swapped back to the OEM spring right quick. I left the Vortek piston seal in there and took a quick chrono test of an 8 shot string. I averaged 724 fps with a high of 733 fps. Now, that is only about 10 fps on average slower than what I was getting before I ever changed anything from OEM. So it's the dadgum spring that is the issue!! 

Seven08, I took the top hat off the Vortek spring and tried to slide the spring over the RWS guide and it's a no go. Coil diameter of the Vortek is too small.

TR

Well thats good. Now you know the Vortek seal works just fine with your Diana spring. Your OEM seal had the same type of damage on it mine did. I see that a lot when guys take it out for the first time. I figure its from those sharp and in some places not very smooth edges on the compression tube cut outs. They must get cut a little when they assemble them. When I broke mine down yesterday I ran my fingers all around the cut outs and deburred them with a file. It made them much smoother so hopefully going forward I won't "nick" another seal.

I'm glad it all worked out for you.

TR

I thought I would give an update on the issues that I had with the Vortek PG2 kit. I just now got it all sorted out...kinda. After contacting Vortek, they really weren't of much help. They did respond to me, but had no real answer. So I ordered a second PG2 HO and installed it. It gave even worse performance. First PG2 yielded an AV of 603 fps. Second PG2 yielded AV of 591 fps. The rifle had been thoroughly cleaned and properly lubed before each install. On the second PG2 I also changed seals from the Vortek seal to an ARH Apex seal to see if there would be any difference. None. 

I was very frustrated to say the least. So I decided to go back and reinstall the OEM Diana spring. Before I did, I took the time to really go through the rifle and perform a "home tune" , I guess you could call it. I had already de-burred all the cut outs in the compression tube. They were fine and really smooth with no rough/sharp edges. I also polished the end of the cocking arm that slides into the piston because it had rough edges on it. It was then lubed with ARH super moly paste. I polished the piston wall on both ends where it was obvious there was contact with the compression tube and lubed with moly paste also. The spring ends on the OEM spring were kinda rough, so they got a good polishing also until the ends were slick and shiny and more moly paste there too...as well as along the entire length of the spring. The OEM guide got a light coating of clear tar. I also installed another ARH Apex piston seal.

There were several other things that I did to the rifle, but not all that important to keep on and on about it I guess. But the end result is a rifle that is smooth to cock and fire. And the best part....I have a full power 34 again. The chrono results were an AV of 724 Fps! I was sooo happy!!!! And the accuracy is excellent as well. I really do not know for the life of me why the Vortek kit does not work in my gun.....but it don't!! I see that it does well in others, but I am done with them. I'm glad that things turned out this way though to be honest with you. I learned a lot through this process. It was a lot of tedious work, but the things that I ended up doing myself was so well worth it. I'm pretty damn familiar with the inner workings of this rifle now, and it shoots so darn smooth.

Long read I know, but I wanted to share the trip.

Thanks...TR

Thanks for the update, TR. When spring break time comes, and it will, the Vortek better than OEM replacement spring is # 810125-31. I have two of them and two Pro-Seals for spares in the event the two Vortek's on duty give it up. Both my D34's now have a Vortex 4-12X , no more sharing.

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Thank you for the replacement spring part #. I've written that down in my little book. I'm pretty sure your happy to have another Vortex. I know it had to have gotten old swapping back and forth all the time. BTW....I got one too! Was sitting on the porch when I got home from work tonight! Some of your posts kinda helped sway me that direction....fixin to open the box in just a bit.

Thanks. TR